Class 12: C Programming Lab Solutions - Complete Guide

C Programming Lab Solutions - Complete Guide

Note for Students: These solutions are provided for your reference and learning. Make sure you understand the logic behind each program before writing them in your copies.

Pointers (Questions 16-20)

16. Print value and memory location using pointer

#include <stdio.h>

int main() {
    int num = 42;
    int *ptr;
    
    ptr = #
    
    printf("Value of num: %d\n", num);
    printf("Memory location of num: %p\n", (void*)&num);
    printf("Value using pointer: %d\n", *ptr);
    printf("Memory location using pointer: %p\n", (void*)ptr);
    
    return 0;
}

Output: Value of num: 42 Memory location of num: 0x7ffd5c8a7b4c Value using pointer: 42 Memory location using pointer: 0x7ffd5c8a7b4c

Note: Memory addresses will vary each time you run the program.

17. Swap two numbers using call-by-value and call-by-reference

#include <stdio.h>

// Call by value - doesn't swap original values
void swapByValue(int a, int b) {
    int temp = a;
    a = b;
    b = temp;
    printf("Inside swapByValue: a = %d, b = %d\n", a, b);
}

// Call by reference - swaps original values
void swapByReference(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

int main() {
    int x = 10, y = 20;
    
    printf("Before swap: x = %d, y = %d\n\n", x, y);
    
    printf("Using Call by Value:\n");
    swapByValue(x, y);
    printf("After swapByValue: x = %d, y = %d\n\n", x, y);
    
    printf("Using Call by Reference:\n");
    swapByReference(&x, &y);
    printf("After swapByReference: x = %d, y = %d\n", x, y);
    
    return 0;
}

Output: Before swap: x = 10, y = 20 Using Call by Value: Inside swapByValue: a = 20, b = 10 After swapByValue: x = 10, y = 20 Using Call by Reference: After swapByReference: x = 20, y = 10

18. Calculate Simple Interest using pointers

#include <stdio.h>

void calculateSI(float *p, float *r, float *t, float *si) {
    *si = (*p * *r * *t) / 100;
}

int main() {
    float principal, rate, time, simpleInterest;
    
    printf("Enter Principal amount: ");
    scanf("%f", &principal);
    printf("Enter Rate of interest: ");
    scanf("%f", &rate);
    printf("Enter Time period (in years): ");
    scanf("%f", &time);
    
    calculateSI(&principal, &rate, &time, &simpleInterest);
    
    printf("\nPrincipal: %.2f\n", principal);
    printf("Rate: %.2f%%\n", rate);
    printf("Time: %.2f years\n", time);
    printf("Simple Interest: %.2f\n", simpleInterest);
    
    return 0;
}

Sample Output: Enter Principal amount: 10000 Enter Rate of interest: 5 Enter Time period (in years): 2 Principal: 10000.00 Rate: 5.00% Time: 2.00 years Simple Interest: 1000.00

19. Calculate volume of cuboid using pointers

#include <stdio.h>

void calculateVolume(float *l, float *w, float *h, float *vol) {
    *vol = (*l) * (*w) * (*h);
}

int main() {
    float length, width, height, volume;
    
    printf("Enter length of cuboid: ");
    scanf("%f", &length);
    printf("Enter width of cuboid: ");
    scanf("%f", &width);
    printf("Enter height of cuboid: ");
    scanf("%f", &height);
    
    calculateVolume(&length, &width, &height, &volume);
    
    printf("\nDimensions: %.2f x %.2f x %.2f\n", length, width, height);
    printf("Volume of cuboid: %.2f cubic units\n", volume);
    
    return 0;
}

Sample Output: Enter length of cuboid: 5 Enter width of cuboid: 4 Enter height of cuboid: 3 Dimensions: 5.00 x 4.00 x 3.00 Volume of cuboid: 60.00 cubic units

20. Reverse a number using pointers

#include <stdio.h>

void reverseNumber(int *num, int *rev) {
    int n = *num;
    *rev = 0;
    
    while(n != 0) {
        *rev = *rev * 10 + n % 10;
        n = n / 10;
    }
}

int main() {
    int number, reversed;
    
    printf("Enter a number: ");
    scanf("%d", &number);
    
    reverseNumber(&number, &reversed);
    
    printf("Original number: %d\n", number);
    printf("Reversed number: %d\n", reversed);
    
    return 0;
}

Sample Output: Enter a number: 12345 Original number: 12345 Reversed number: 54321

Structure and Union (Questions 21-37)

21. Single student details using structure

#include <stdio.h>

struct Student {
    int rollNo;
    char name[50];
    float marks;
};

int main() {
    struct Student s;
    
    printf("Enter Roll Number: ");
    scanf("%d", &s.rollNo);
    printf("Enter Name: ");
    scanf(" %[^\n]", s.name);
    printf("Enter Marks: ");
    scanf("%f", &s.marks);
    
    printf("\n--- Student Details ---\n");
    printf("Roll Number: %d\n", s.rollNo);
    printf("Name: %s\n", s.name);
    printf("Marks: %.2f\n", s.marks);
    
    return 0;
}

Sample Output: Enter Roll Number: 101 Enter Name: John Doe Enter Marks: 85.5 --- Student Details --- Roll Number: 101 Name: John Doe Marks: 85.50

22. 5 students details using structure

#include <stdio.h>

struct Student {
    int rollNo;
    char name[50];
    float marks;
};

int main() {
    struct Student s[5];
    int i;
    
    printf("Enter details of 5 students:\n\n");
    for(i = 0; i < 5; i++) {
        printf("Student %d:\n", i+1);
        printf("Enter Roll Number: ");
        scanf("%d", &s[i].rollNo);
        printf("Enter Name: ");
        scanf(" %[^\n]", s[i].name);
        printf("Enter Marks: ");
        scanf("%f", &s[i].marks);
        printf("\n");
    }
    
    printf("\n--- Details of All Students ---\n");
    for(i = 0; i < 5; i++) {
        printf("\nStudent %d:\n", i+1);
        printf("Roll Number: %d\n", s[i].rollNo);
        printf("Name: %s\n", s[i].name);
        printf("Marks: %.2f\n", s[i].marks);
    }
    
    return 0;
}

Sample Output: Enter details of 5 students: Student 1: Enter Roll Number: 101 Enter Name: Alice Enter Marks: 88.5 Student 2: Enter Roll Number: 102 Enter Name: Bob Enter Marks: 92.0 [... continues for all 5 students ...] --- Details of All Students --- Student 1: Roll Number: 101 Name: Alice Marks: 88.50 Student 2: Roll Number: 102 Name: Bob Marks: 92.00

23. N employees details using structure

#include <stdio.h>

struct Employee {
    int empId;
    char empName[50];
    float salary;
};

int main() {
    int n, i;
    
    printf("Enter number of employees: ");
    scanf("%d", &n);
    
    struct Employee emp[n];
    
    printf("\nEnter details of %d employees:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Employee %d:\n", i+1);
        printf("Enter Employee ID: ");
        scanf("%d", &emp[i].empId);
        printf("Enter Employee Name: ");
        scanf(" %[^\n]", emp[i].empName);
        printf("Enter Salary: ");
        scanf("%f", &emp[i].salary);
        printf("\n");
    }
    
    printf("\n--- Details of All Employees ---\n");
    for(i = 0; i < n; i++) {
        printf("\nEmployee %d:\n", i+1);
        printf("Employee ID: %d\n", emp[i].empId);
        printf("Employee Name: %s\n", emp[i].empName);
        printf("Salary: %.2f\n", emp[i].salary);
    }
    
    return 0;
}

Sample Output: Enter number of employees: 3 Enter details of 3 employees: Employee 1: Enter Employee ID: 1001 Enter Employee Name: Sarah Johnson Enter Salary: 45000 Employee 2: Enter Employee ID: 1002 Enter Employee Name: Mike Chen Enter Salary: 52000 Employee 3: Enter Employee ID: 1003 Enter Employee Name: Emma Davis Enter Salary: 48000 --- Details of All Employees --- Employee 1: Employee ID: 1001 Employee Name: Sarah Johnson Salary: 45000.00 Employee 2: Employee ID: 1002 Employee Name: Mike Chen Salary: 52000.00 Employee 3: Employee ID: 1003 Employee Name: Emma Davis Salary: 48000.00

24. 3 books details using structure

#include <stdio.h>

struct Book {
    int bookId;
    char title[100];
    float price;
    char isbn[20];
};

int main() {
    struct Book b[3];
    int i;
    
    printf("Enter details of 3 books:\n\n");
    for(i = 0; i < 3; i++) {
        printf("Book %d:\n", i+1);
        printf("Enter Book ID: ");
        scanf("%d", &b[i].bookId);
        printf("Enter Title: ");
        scanf(" %[^\n]", b[i].title);
        printf("Enter Price: ");
        scanf("%f", &b[i].price);
        printf("Enter ISBN: ");
        scanf(" %[^\n]", b[i].isbn);
        printf("\n");
    }
    
    printf("\n--- Details of All Books ---\n");
    for(i = 0; i < 3; i++) {
        printf("\nBook %d:\n", i+1);
        printf("Book ID: %d\n", b[i].bookId);
        printf("Title: %s\n", b[i].title);
        printf("Price: %.2f\n", b[i].price);
        printf("ISBN: %s\n", b[i].isbn);
    }
    
    return 0;
}

Sample Output: Enter details of 3 books: Book 1: Enter Book ID: 501 Enter Title: The C Programming Language Enter Price: 650.50 Enter ISBN: 978-0131103628 Book 2: Enter Book ID: 502 Enter Title: Data Structures in C Enter Price: 550.00 Enter ISBN: 978-0201549881 Book 3: Enter Book ID: 503 Enter Title: Computer Networks Enter Price: 720.00 Enter ISBN: 978-0133763222 --- Details of All Books --- Book 1: Book ID: 501 Title: The C Programming Language Price: 650.50 ISBN: 978-0131103628 Book 2: Book ID: 502 Title: Data Structures in C Price: 550.00 ISBN: 978-0201549881 Book 3: Book ID: 503 Title: Computer Networks Price: 720.00 ISBN: 978-0133763222

25. N products details using structure

#include <stdio.h>

struct Product {
    int productId;
    char productName[50];
    float price;
};

int main() {
    int n, i;
    
    printf("Enter number of products: ");
    scanf("%d", &n);
    
    struct Product p[n];
    
    printf("\nEnter details of %d products:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Product %d:\n", i+1);
        printf("Enter Product ID: ");
        scanf("%d", &p[i].productId);
        printf("Enter Product Name: ");
        scanf(" %[^\n]", p[i].productName);
        printf("Enter Price: ");
        scanf("%f", &p[i].price);
        printf("\n");
    }
    
    printf("\n--- Details of All Products ---\n");
    for(i = 0; i < n; i++) {
        printf("\nProduct %d:\n", i+1);
        printf("Product ID: %d\n", p[i].productId);
        printf("Product Name: %s\n", p[i].productName);
        printf("Price: %.2f\n", p[i].price);
    }
    
    return 0;
}

Sample Output: Enter number of products: 2 Enter details of 2 products: Product 1: Enter Product ID: 201 Enter Product Name: Laptop Enter Price: 45000 Product 2: Enter Product ID: 202 Enter Product Name: Mouse Enter Price: 500 --- Details of All Products --- Product 1: Product ID: 201 Product Name: Laptop Price: 45000.00 Product 2: Product ID: 202 Product Name: Mouse Price: 500.00

26. N bank accounts details using structure

#include <stdio.h>

struct BankAccount {
    long accountNumber;
    char accountHolderName[50];
    char accountType[20];
    float balance;
};

int main() {
    int n, i;
    
    printf("Enter number of bank accounts: ");
    scanf("%d", &n);
    
    struct BankAccount acc[n];
    
    printf("\nEnter details of %d bank accounts:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Account %d:\n", i+1);
        printf("Enter Account Number: ");
        scanf("%ld", &acc[i].accountNumber);
        printf("Enter Account Holder Name: ");
        scanf(" %[^\n]", acc[i].accountHolderName);
        printf("Enter Account Type (Savings/Current): ");
        scanf(" %[^\n]", acc[i].accountType);
        printf("Enter Balance: ");
        scanf("%f", &acc[i].balance);
        printf("\n");
    }
    
    printf("\n--- Details of All Bank Accounts ---\n");
    for(i = 0; i < n; i++) {
        printf("\nAccount %d:\n", i+1);
        printf("Account Number: %ld\n", acc[i].accountNumber);
        printf("Account Holder Name: %s\n", acc[i].accountHolderName);
        printf("Account Type: %s\n", acc[i].accountType);
        printf("Balance: %.2f\n", acc[i].balance);
    }
    
    return 0;
}

Sample Output: Enter number of bank accounts: 2 Enter details of 2 bank accounts: Account 1: Enter Account Number: 1234567890 Enter Account Holder Name: John Smith Enter Account Type (Savings/Current): Savings Enter Balance: 50000 Account 2: Enter Account Number: 9876543210 Enter Account Holder Name: Mary Jane Enter Account Type (Savings/Current): Current Enter Balance: 75000 --- Details of All Bank Accounts --- Account 1: Account Number: 1234567890 Account Holder Name: John Smith Account Type: Savings Balance: 50000.00 Account 2: Account Number: 9876543210 Account Holder Name: Mary Jane Account Type: Current Balance: 75000.00

27. Citizens with age > 18 using structure

#include <stdio.h>

struct Citizen {
    int citizenId;
    char name[50];
    int age;
};

int main() {
    int n, i;
    
    printf("Enter number of citizens: ");
    scanf("%d", &n);
    
    struct Citizen c[n];
    
    printf("\nEnter details of %d citizens:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Citizen %d:\n", i+1);
        printf("Enter Citizen ID: ");
        scanf("%d", &c[i].citizenId);
        printf("Enter Name: ");
        scanf(" %[^\n]", c[i].name);
        printf("Enter Age: ");
        scanf("%d", &c[i].age);
        printf("\n");
    }
    
    printf("\n--- Citizens with Age Greater Than 18 ---\n");
    for(i = 0; i < n; i++) {
        if(c[i].age > 18) {
            printf("\nCitizen ID: %d\n", c[i].citizenId);
            printf("Name: %s\n", c[i].name);
            printf("Age: %d\n", c[i].age);
        }
    }
    
    return 0;
}

Sample Output: Enter number of citizens: 4 Enter details of 4 citizens: Citizen 1: Enter Citizen ID: 1001 Enter Name: Alice Brown Enter Age: 25 Citizen 2: Enter Citizen ID: 1002 Enter Name: Tommy Lee Enter Age: 16 Citizen 3: Enter Citizen ID: 1003 Enter Name: Sarah Wilson Enter Age: 22 Citizen 4: Enter Citizen ID: 1004 Enter Name: Jake Miller Enter Age: 17 --- Citizens with Age Greater Than 18 --- Citizen ID: 1001 Name: Alice Brown Age: 25 Citizen ID: 1003 Name: Sarah Wilson Age: 22

28. Movies with rating equal to 8 using structure

#include <stdio.h>

struct Movie {
    int movieId;
    char title[100];
    int rating;
};

int main() {
    int n, i;
    
    printf("Enter number of movies: ");
    scanf("%d", &n);
    
    struct Movie m[n];
    
    printf("\nEnter details of %d movies:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Movie %d:\n", i+1);
        printf("Enter Movie ID: ");
        scanf("%d", &m[i].movieId);
        printf("Enter Title: ");
        scanf(" %[^\n]", m[i].title);
        printf("Enter Rating (1-10): ");
        scanf("%d", &m[i].rating);
        printf("\n");
    }
    
    printf("\n--- Movies with Rating Equal to 8 ---\n");
    for(i = 0; i < n; i++) {
        if(m[i].rating == 8) {
            printf("\nMovie ID: %d\n", m[i].movieId);
            printf("Title: %s\n", m[i].title);
            printf("Rating: %d\n", m[i].rating);
        }
    }
    
    return 0;
}

Sample Output: Enter number of movies: 4 Enter details of 4 movies: Movie 1: Enter Movie ID: 301 Enter Title: Inception Enter Rating (1-10): 9 Movie 2: Enter Movie ID: 302 Enter Title: The Dark Knight Enter Rating (1-10): 8 Movie 3: Enter Movie ID: 303 Enter Title: Interstellar Enter Rating (1-10): 8 Movie 4: Enter Movie ID: 304 Enter Title: Avatar Enter Rating (1-10): 7 --- Movies with Rating Equal to 8 --- Movie ID: 302 Title: The Dark Knight Rating: 8 Movie ID: 303 Title: Interstellar Rating: 8

29. Books with genre "Horror" using structure

#include <stdio.h>
#include <string.h>

struct Book {
    char authorName[50];
    char genre[30];
    float price;
    char isbn[20];
};

int main() {
    int n, i;
    
    printf("Enter number of books: ");
    scanf("%d", &n);
    
    struct Book b[n];
    
    printf("\nEnter details of %d books:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Book %d:\n", i+1);
        printf("Enter Author Name: ");
        scanf(" %[^\n]", b[i].authorName);
        printf("Enter Genre: ");
        scanf(" %[^\n]", b[i].genre);
        printf("Enter Price: ");
        scanf("%f", &b[i].price);
        printf("Enter ISBN: ");
        scanf(" %[^\n]", b[i].isbn);
        printf("\n");
    }
    
    printf("\n--- Books with Genre 'Horror' ---\n");
    for(i = 0; i < n; i++) {
        if(strcmp(b[i].genre, "Horror") == 0) {
            printf("\nAuthor Name: %s\n", b[i].authorName);
            printf("Genre: %s\n", b[i].genre);
            printf("Price: %.2f\n", b[i].price);
            printf("ISBN: %s\n", b[i].isbn);
        }
    }
    
    return 0;
}

Sample Output: Enter number of books: 3 Enter details of 3 books: Book 1: Enter Author Name: Stephen King Enter Genre: Horror Enter Price: 450.00 Enter ISBN: 978-0385121675 Book 2: Enter Author Name: J.K. Rowling Enter Genre: Fantasy Enter Price: 550.00 Enter ISBN: 978-0439708180 Book 3: Enter Author Name: Edgar Allan Poe Enter Genre: Horror Enter Price: 350.00 Enter ISBN: 978-0143122364 --- Books with Genre 'Horror' --- Author Name: Stephen King Genre: Horror Price: 450.00 ISBN: 978-0385121675 Author Name: Edgar Allan Poe Genre: Horror Price: 350.00 ISBN: 978-0143122364

30. Employees in Finance department using structure

#include <stdio.h>
#include <string.h>

struct Employee {
    char name[50];
    char address[100];
    char department[30];
    float salary;
};

int main() {
    int n, i;
    
    printf("Enter number of employees: ");
    scanf("%d", &n);
    
    struct Employee emp[n];
    
    printf("\nEnter details of %d employees:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Employee %d:\n", i+1);
        printf("Enter Name: ");
        scanf(" %[^\n]", emp[i].name);
        printf("Enter Address: ");
        scanf(" %[^\n]", emp[i].address);
        printf("Enter Department: ");
        scanf(" %[^\n]", emp[i].department);
        printf("Enter Salary: ");
        scanf("%f", &emp[i].salary);
        printf("\n");
    }
    
    printf("\n--- Employees in Finance Department ---\n");
    for(i = 0; i < n; i++) {
        if(strcmp(emp[i].department, "Finance") == 0) {
            printf("\nName: %s\n", emp[i].name);
            printf("Address: %s\n", emp[i].address);
            printf("Department: %s\n", emp[i].department);
            printf("Salary: %.2f\n", emp[i].salary);
        }
    }
    
    return 0;
}

Sample Output: Enter number of employees: 4 Enter details of 4 employees: Employee 1: Enter Name: Robert Smith Enter Address: 123 Main St Enter Department: Finance Enter Salary: 55000 Employee 2: Enter Name: Lisa Johnson Enter Address: 456 Oak Ave Enter Department: IT Enter Salary: 60000 Employee 3: Enter Name: David Lee Enter Address: 789 Pine Rd Enter Department: Finance Enter Salary: 58000 Employee 4: Enter Name: Anna White Enter Address: 321 Elm St Enter Department: HR Enter Salary: 52000 --- Employees in Finance Department --- Name: Robert Smith Address: 123 Main St Department: Finance Salary: 55000.00 Name: David Lee Address: 789 Pine Rd Department: Finance Salary: 58000.00

31. Sort students by name in ascending order

#include <stdio.h>
#include <string.h>

struct Student {
    int rollNo;
    char name[50];
    float marks;
};

int main() {
    int n, i, j;
    struct Student temp;
    
    printf("Enter number of students: ");
    scanf("%d", &n);
    
    struct Student s[n];
    
    printf("\nEnter details of %d students:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Student %d:\n", i+1);
        printf("Enter Roll Number: ");
        scanf("%d", &s[i].rollNo);
        printf("Enter Name: ");
        scanf(" %[^\n]", s[i].name);
        printf("Enter Marks: ");
        scanf("%f", &s[i].marks);
        printf("\n");
    }
    
    // Bubble sort by name
    for(i = 0; i < n-1; i++) {
        for(j = 0; j < n-i-1; j++) {
            if(strcmp(s[j].name, s[j+1].name) > 0) {
                temp = s[j];
                s[j] = s[j+1];
                s[j+1] = temp;
            }
        }
    }
    
    printf("\n--- Students Sorted by Name (Ascending) ---\n");
    for(i = 0; i < n; i++) {
        printf("\nRoll Number: %d\n", s[i].rollNo);
        printf("Name: %s\n", s[i].name);
        printf("Marks: %.2f\n", s[i].marks);
    }
    
    return 0;
}

Sample Output: Enter number of students: 3 Enter details of 3 students: Student 1: Enter Roll Number: 103 Enter Name: Charlie Enter Marks: 78 Student 2: Enter Roll Number: 101 Enter Name: Alice Enter Marks: 85 Student 3: Enter Roll Number: 102 Enter Name: Bob Enter Marks: 92 --- Students Sorted by Name (Ascending) --- Roll Number: 101 Name: Alice Marks: 85.00 Roll Number: 102 Name: Bob Marks: 92.00 Roll Number: 103 Name: Charlie Marks: 78.00

32. Sort employees by salary in descending order

#include <stdio.h>

struct Employee {
    int empId;
    char empName[50];
    float salary;
};

int main() {
    int n, i, j;
    struct Employee temp;
    
    printf("Enter number of employees: ");
    scanf("%d", &n);
    
    struct Employee emp[n];
    
    printf("\nEnter details of %d employees:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Employee %d:\n", i+1);
        printf("Enter Employee ID: ");
        scanf("%d", &emp[i].empId);
        printf("Enter Employee Name: ");
        scanf(" %[^\n]", emp[i].empName);
        printf("Enter Salary: ");
        scanf("%f", &emp[i].salary);
        printf("\n");
    }
    
    // Bubble sort by salary (descending)
    for(i = 0; i < n-1; i++) {
        for(j = 0; j < n-i-1; j++) {
            if(emp[j].salary < emp[j+1].salary) {
                temp = emp[j];
                emp[j] = emp[j+1];
                emp[j+1] = temp;
            }
        }
    }
    
    printf("\n--- Employees Sorted by Salary (Descending) ---\n");
    for(i = 0; i < n; i++) {
        printf("\nEmployee ID: %d\n", emp[i].empId);
        printf("Employee Name: %s\n", emp[i].empName);
        printf("Salary: %.2f\n", emp[i].salary);
    }
    
    return 0;
}

Sample Output: Enter number of employees: 4 Enter details of 4 employees: Employee 1: Enter Employee ID: 1001 Enter Employee Name: John Enter Salary: 45000 Employee 2: Enter Employee ID: 1002 Enter Employee Name: Sarah Enter Salary: 60000 Employee 3: Enter Employee ID: 1003 Enter Employee Name: Mike Enter Salary: 52000 Employee 4: Enter Employee ID: 1004 Enter Employee Name: Emma Enter Salary: 48000 --- Employees Sorted by Salary (Descending) --- Employee ID: 1002 Employee Name: Sarah Salary: 60000.00 Employee ID: 1003 Employee Name: Mike Salary: 52000.00 Employee ID: 1004 Employee Name: Emma Salary: 48000.00 Employee ID: 1001 Employee Name: John Salary: 45000.00

33. Product with 3rd highest price using structure

#include <stdio.h>

struct Product {
    char productName[50];
    char brand[30];
    float price;
    int quantity;
};

int main() {
    int n, i, j;
    struct Product temp;
    
    printf("Enter number of products: ");
    scanf("%d", &n);
    
    struct Product p[n];
    
    printf("\nEnter details of %d products:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Product %d:\n", i+1);
        printf("Enter Product Name: ");
        scanf(" %[^\n]", p[i].productName);
        printf("Enter Brand: ");
        scanf(" %[^\n]", p[i].brand);
        printf("Enter Price: ");
        scanf("%f", &p[i].price);
        printf("Enter Quantity: ");
        scanf("%d", &p[i].quantity);
        printf("\n");
    }
    
    // Bubble sort by price (descending)
    for(i = 0; i < n-1; i++) {
        for(j = 0; j < n-i-1; j++) {
            if(p[j].price < p[j+1].price) {
                temp = p[j];
                p[j] = p[j+1];
                p[j+1] = temp;
            }
        }
    }
    
    if(n >= 3) {
        printf("\n--- Product with 3rd Highest Price ---\n");
        printf("Product Name: %s\n", p[2].productName);
        printf("Brand: %s\n", p[2].brand);
        printf("Price: %.2f\n", p[2].price);
        printf("Quantity: %d\n", p[2].quantity);
    } else {
        printf("Not enough products to find 3rd highest price.\n");
    }
    
    return 0;
}

Sample Output: Enter number of products: 5 Enter details of 5 products: Product 1: Enter Product Name: Laptop Enter Brand: Dell Enter Price: 55000 Enter Quantity: 10 Product 2: Enter Product Name: Phone Enter Brand: Samsung Enter Price: 25000 Enter Quantity: 20 Product 3: Enter Product Name: Tablet Enter Brand: Apple Enter Price: 40000 Enter Quantity: 15 Product 4: Enter Product Name: Watch Enter Brand: Apple Enter Price: 35000 Enter Quantity: 25 Product 5: Enter Product Name: Headphones Enter Brand: Sony Enter Price: 8000 Enter Quantity: 30 --- Product with 3rd Highest Price --- Product Name: Tablet Brand: Apple Price: 40000.00 Quantity: 15

34. Bank accounts with holder name starting with 'C'

#include <stdio.h>

struct BankAccount {
    long account_no;
    char holder_name[50];
    float balance;
    char account_type[20];
};

int main() {
    int n, i;
    
    printf("Enter number of bank accounts: ");
    scanf("%d", &n);
    
    struct BankAccount acc[n];
    
    printf("\nEnter details of %d bank accounts:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Account %d:\n", i+1);
        printf("Enter Account Number: ");
        scanf("%ld", &acc[i].account_no);
        printf("Enter Holder Name: ");
        scanf(" %[^\n]", acc[i].holder_name);
        printf("Enter Balance: ");
        scanf("%f", &acc[i].balance);
        printf("Enter Account Type: ");
        scanf(" %[^\n]", acc[i].account_type);
        printf("\n");
    }
    
    printf("\n--- Accounts with Holder Name Starting with 'C' ---\n");
    for(i = 0; i < n; i++) {
        if(acc[i].holder_name[0] == 'C' || acc[i].holder_name[0] == 'c') {
            printf("\nAccount Number: %ld\n", acc[i].account_no);
            printf("Holder Name: %s\n", acc[i].holder_name);
            printf("Balance: %.2f\n", acc[i].balance);
            printf("Account Type: %s\n", acc[i].account_type);
        }
    }
    
    return 0;
}

Sample Output: Enter number of bank accounts: 4 Enter details of 4 bank accounts: Account 1: Enter Account Number: 1001 Enter Holder Name: Charlie Brown Enter Balance: 50000 Enter Account Type: Savings Account 2: Enter Account Number: 1002 Enter Holder Name: Alice Smith Enter Balance: 75000 Enter Account Type: Current Account 3: Enter Account Number: 1003 Enter Holder Name: Catherine Jones Enter Balance: 60000 Enter Account Type: Savings Account 4: Enter Account Number: 1004 Enter Holder Name: Bob Williams Enter Balance: 45000 Enter Account Type: Current --- Accounts with Holder Name Starting with 'C' --- Account Number: 1001 Holder Name: Charlie Brown Balance: 50000.00 Account Type: Savings Account Number: 1003 Holder Name: Catherine Jones Balance: 60000.00 Account Type: Savings

35. Nested structure - Student with Address

#include <stdio.h>

struct Address {
    int houseNo;
    char street[50];
    char city[30];
};

struct Student {
    int rollNo;
    char name[50];
    float marks;
    struct Address addr;
};

int main() {
    int n, i;
    
    printf("Enter number of students: ");
    scanf("%d", &n);
    
    struct Student s[n];
    
    printf("\nEnter details of %d students:\n\n", n);
    for(i = 0; i < n; i++) {
        printf("Student %d:\n", i+1);
        printf("Enter Roll Number: ");
        scanf("%d", &s[i].rollNo);
        printf("Enter Name: ");
        scanf(" %[^\n]", s[i].name);
        printf("Enter Marks: ");
        scanf("%f", &s[i].marks);
        printf("Enter House Number: ");
        scanf("%d", &s[i].addr.houseNo);
        printf("Enter Street: ");
        scanf(" %[^\n]", s[i].addr.street);
        printf("Enter City: ");
        scanf(" %[^\n]", s[i].addr.city);
        printf("\n");
    }
    
    printf("\n--- Student Details with Address ---\n");
    for(i = 0; i < n; i++) {
        printf("\nStudent %d:\n", i+1);
        printf("Roll Number: %d\n", s[i].rollNo);
        printf("Name: %s\n", s[i].name);
        printf("Marks: %.2f\n", s[i].marks);
        printf("Address: House No. %d, %s, %s\n", 
               s[i].addr.houseNo, s[i].addr.street, s[i].addr.city);
    }
    
    return 0;
}

Sample Output: Enter number of students: 2 Enter details of 2 students: Student 1: Enter Roll Number: 101 Enter Name: Alex Johnson Enter Marks: 88.5 Enter House Number: 123 Enter Street: Oak Street Enter City: New York Student 2: Enter Roll Number: 102 Enter Name: Maria Garcia Enter Marks: 92.0 Enter House Number: 456 Enter Street: Maple Avenue Enter City: Boston --- Student Details with Address --- Student 1: Roll Number: 101 Name: Alex Johnson Marks: 88.50 Address: House No. 123, Oak Street, New York Student 2: Roll Number: 102 Name: Maria Garcia Marks: 92.00 Address: House No. 456, Maple Avenue, Boston

36. Union with different data types

#include <stdio.h>

union Data {
    int intValue;
    float floatValue;
    char charValue;
};

int main() {
    union Data d;
    
    printf("Size of union: %lu bytes\n\n", sizeof(d));
    
    d.intValue = 42;
    printf("Storing integer value:\n");
    printf("Integer value: %d\n\n", d.intValue);
    
    d.floatValue = 3.14;
    printf("Storing float value (overwrites previous):\n");
    printf("Float value: %.2f\n", d.floatValue);
    printf("Integer value (corrupted): %d\n\n", d.intValue);
    
    d.charValue = 'A';
    printf("Storing char value (overwrites previous):\n");
    printf("Char value: %c\n", d.charValue);
    printf("Integer value (corrupted): %d\n", d.intValue);
    printf("Float value (corrupted): %.2f\n\n", d.floatValue);
    
    printf("Note: Union shares same memory for all members.\n");
    printf("Only one member can hold a valid value at a time.\n");
    
    return 0;
}

Output: Size of union: 4 bytes Storing integer value: Integer value: 42 Storing float value (overwrites previous): Float value: 3.14 Integer value (corrupted): 1078523331 Storing char value (overwrites previous): Char value: A Integer value (corrupted): 65 Float value (corrupted): 0.00 Note: Union shares same memory for all members. Only one member can hold a valid value at a time.

37. Union for 10 employees

#include <stdio.h>

union Employee {
    int empId;
    float salary;
    char grade;
};

int main() {
    union Employee emp[10];
    int i;
    
    printf("Enter Employee IDs for 10 employees:\n");
    for(i = 0; i < 10; i++) {
        printf("Employee %d ID: ", i+1);
        scanf("%d", &emp[i].empId);
    }
    
    printf("\n--- Employee IDs ---\n");
    for(i = 0; i < 10; i++) {
        printf("Employee %d: %d\n", i+1, emp[i].empId);
    }
    
    printf("\nEnter Salaries for 10 employees:\n");
    for(i = 0; i < 10; i++) {
        printf("Employee %d Salary: ", i+1);
        scanf("%f", &emp[i].salary);
    }
    
    printf("\n--- Employee Salaries ---\n");
    for(i = 0; i < 10; i++) {
        printf("Employee %d: %.2f\n", i+1, emp[i].salary);
    }
    
    printf("\nEnter Grades for 10 employees:\n");
    for(i = 0; i < 10; i++) {
        printf("Employee %d Grade: ", i+1);
        scanf(" %c", &emp[i].grade);
    }
    
    printf("\n--- Employee Grades ---\n");
    for(i = 0; i < 10; i++) {
        printf("Employee %d: %c\n", i+1, emp[i].grade);
    }
    
    printf("\nNote: Each union element can store only one value at a time.\n");
    
    return 0;
}

Sample Output: Enter Employee IDs for 10 employees: Employee 1 ID: 101 Employee 2 ID: 102 [... continues for all 10 ...] --- Employee IDs --- Employee 1: 101 Employee 2: 102 [... continues for all 10 ...] Enter Salaries for 10 employees: Employee 1 Salary: 45000 Employee 2 Salary: 50000 [... continues for all 10 ...] --- Employee Salaries --- Employee 1: 45000.00 Employee 2: 50000.00 [... continues for all 10 ...] Enter Grades for 10 employees: Employee 1 Grade: A Employee 2 Grade: B [... continues for all 10 ...] --- Employee Grades --- Employee 1: A Employee 2: B [... continues for all 10 ...] Note: Each union element can store only one value at a time.

File Handling (Questions 38-44)

38. File handling with putc(), getc(), putw(), getw()

#include <stdio.h>

int main() {
    FILE *fp;
    char ch;
    int num;
    
    // Writing to file
    fp = fopen("data.txt", "w");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    // Writing characters using putc()
    putc('H', fp);
    putc('e', fp);
    putc('l', fp);
    putc('l', fp);
    putc('o', fp);
    putc('\n', fp);
    
    fclose(fp);
    
    // Writing integers using putw()
    fp = fopen("numbers.txt", "w");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    putw(100, fp);
    putw(200, fp);
    putw(300, fp);
    
    fclose(fp);
    
    // Reading characters using getc()
    printf("Reading characters from file:\n");
    fp = fopen("data.txt", "r");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    while((ch = getc(fp)) != EOF) {
        printf("%c", ch);
    }
    
    fclose(fp);
    
    // Reading integers using getw()
    printf("\nReading integers from file:\n");
    fp = fopen("numbers.txt", "r");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    while((num = getw(fp)) != EOF) {
        printf("%d ", num);
    }
    printf("\n");
    
    fclose(fp);
    
    return 0;
}

Output: Reading characters from file: Hello Reading integers from file: 100 200 300

39. Store and read student details from file

#include <stdio.h>

struct Student {
    int rollNo;
    char name[50];
    float marks;
};

int main() {
    FILE *fp;
    struct Student s;
    int n, i;
    
    // Writing to file
    fp = fopen("students.dat", "wb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("Enter number of students: ");
    scanf("%d", &n);
    
    printf("\nEnter student details:\n");
    for(i = 0; i < n; i++) {
        printf("\nStudent %d:\n", i+1);
        printf("Roll Number: ");
        scanf("%d", &s.rollNo);
        printf("Name: ");
        scanf(" %[^\n]", s.name);
        printf("Marks: ");
        scanf("%f", &s.marks);
        
        fwrite(&s, sizeof(struct Student), 1, fp);
    }
    
    fclose(fp);
    printf("\nStudent records saved successfully!\n");
    
    // Reading from file
    fp = fopen("students.dat", "rb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("\n--- Student Records from File ---\n");
    i = 1;
    while(fread(&s, sizeof(struct Student), 1, fp) == 1) {
        printf("\nStudent %d:\n", i++);
        printf("Roll Number: %d\n", s.rollNo);
        printf("Name: %s\n", s.name);
        printf("Marks: %.2f\n", s.marks);
    }
    
    fclose(fp);
    
    return 0;
}

Sample Output: Enter number of students: 2 Enter student details: Student 1: Roll Number: 101 Name: John Smith Marks: 85.5 Student 2: Roll Number: 102 Name: Emma Wilson Marks: 92.0 Student records saved successfully! --- Student Records from File --- Student 1: Roll Number: 101 Name: John Smith Marks: 85.50 Student 2: Roll Number: 102 Name: Emma Wilson Marks: 92.00

40. Store and read employee details from file

#include <stdio.h>

struct Employee {
    int empId;
    char name[50];
    float salary;
};

int main() {
    FILE *fp;
    struct Employee emp;
    int n, i;
    
    // Writing to file
    fp = fopen("employees.dat", "wb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("Enter number of employees: ");
    scanf("%d", &n);
    
    printf("\nEnter employee details:\n");
    for(i = 0; i < n; i++) {
        printf("\nEmployee %d:\n", i+1);
        printf("Employee ID: ");
        scanf("%d", &emp.empId);
        printf("Name: ");
        scanf(" %[^\n]", emp.name);
        printf("Salary: ");
        scanf("%f", &emp.salary);
        
        fwrite(&emp, sizeof(struct Employee), 1, fp);
    }
    
    fclose(fp);
    printf("\nEmployee records saved successfully!\n");
    
    // Reading from file
    fp = fopen("employees.dat", "rb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("\n--- Employee Records from File ---\n");
    i = 1;
    while(fread(&emp, sizeof(struct Employee), 1, fp) == 1) {
        printf("\nEmployee %d:\n", i++);
        printf("Employee ID: %d\n", emp.empId);
        printf("Name: %s\n", emp.name);
        printf("Salary: %.2f\n", emp.salary);
    }
    
    fclose(fp);
    
    return 0;
}

Sample Output: Enter number of employees: 2 Enter employee details: Employee 1: Employee ID: 1001 Name: Sarah Johnson Salary: 55000 Employee 2: Employee ID: 1002 Name: Michael Brown Salary: 60000 Employee records saved successfully! --- Employee Records from File --- Employee 1: Employee ID: 1001 Name: Sarah Johnson Salary: 55000.00 Employee 2: Employee ID: 1002 Name: Michael Brown Salary: 60000.00

41. Store 5 books and display books with price > 500

#include <stdio.h>

struct Book {
    int bookId;
    char title[100];
    float price;
};

int main() {
    FILE *fp;
    struct Book b;
    int i;
    
    // Writing to file
    fp = fopen("books.dat", "wb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("Enter details of 5 books:\n");
    for(i = 0; i < 5; i++) {
        printf("\nBook %d:\n", i+1);
        printf("Book ID: ");
        scanf("%d", &b.bookId);
        printf("Title: ");
        scanf(" %[^\n]", b.title);
        printf("Price: ");
        scanf("%f", &b.price);
        
        fwrite(&b, sizeof(struct Book), 1, fp);
    }
    
    fclose(fp);
    printf("\nBook records saved successfully!\n");
    
    // Reading from file and filtering
    fp = fopen("books.dat", "rb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("\n--- Books with Price Greater Than 500 ---\n");
    while(fread(&b, sizeof(struct Book), 1, fp) == 1) {
        if(b.price > 500) {
            printf("\nBook ID: %d\n", b.bookId);
            printf("Title: %s\n", b.title);
            printf("Price: %.2f\n", b.price);
        }
    }
    
    fclose(fp);
    
    return 0;
}

Sample Output: Enter details of 5 books: Book 1: Book ID: 501 Book ID: The C Programming Language Price: 650 Book 2: Book ID: 502 Title: Data Structures Price: 450 Book 3: Book ID: 503 Title: Algorithms Price: 720 Book 4: Book ID: 504 Title: Operating Systems Price: 550 Book 5: Book ID: 505 Title: Database Systems Price: 480 Book records saved successfully! --- Books with Price Greater Than 500 --- Book ID: 501 Title: The C Programming Language Price: 650.00 Book ID: 503 Title: Algorithms Price: 720.00 Book ID: 504 Title: Operating Systems Price: 550.00

42. Store products and display Nike products

#include <stdio.h>
#include <string.h>

struct Product {
    int productId;
    char productName[50];
    char brand[30];
    float price;
};

int main() {
    FILE *fp;
    struct Product p;
    int n, i;
    
    // Writing to file
    fp = fopen("products.dat", "wb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("Enter number of products: ");
    scanf("%d", &n);
    
    printf("\nEnter product details:\n");
    for(i = 0; i < n; i++) {
        printf("\nProduct %d:\n", i+1);
        printf("Product ID: ");
        scanf("%d", &p.productId);
        printf("Product Name: ");
        scanf(" %[^\n]", p.productName);
        printf("Brand: ");
        scanf(" %[^\n]", p.brand);
        printf("Price: ");
        scanf("%f", &p.price);
        
        fwrite(&p, sizeof(struct Product), 1, fp);
    }
    
    fclose(fp);
    printf("\nProduct records saved successfully!\n");
    
    // Reading from file and filtering
    fp = fopen("products.dat", "rb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("\n--- Nike Products ---\n");
    while(fread(&p, sizeof(struct Product), 1, fp) == 1) {
        if(strcmp(p.brand, "Nike") == 0) {
            printf("\nProduct ID: %d\n", p.productId);
            printf("Product Name: %s\n", p.productName);
            printf("Brand: %s\n", p.brand);
            printf("Price: %.2f\n", p.price);
        }
    }
    
    fclose(fp);
    
    return 0;
}

Sample Output: Enter number of products: 4 Enter product details: Product 1: Product ID: 201 Product Name: Running Shoes Brand: Nike Price: 3500 Product 2: Product ID: 202 Product Name: Sports Watch Brand: Casio Price: 2500 Product 3: Product ID: 203 Product Name: Training Shoes Brand: Nike Price: 4200 Product 4: Product ID: 204 Product Name: Basketball Brand: Spalding Price: 1500 Product records saved successfully! --- Nike Products --- Product ID: 201 Product Name: Running Shoes Brand: Nike Price: 3500.00 Product ID: 203 Product Name: Training Shoes Brand: Nike Price: 4200.00

43. Store and read bank account details from file

#include <stdio.h>

struct BankAccount {
    long accountNumber;
    char accountHolderName[50];
    float balance;
};

int main() {
    FILE *fp;
    struct BankAccount acc;
    int n, i;
    
    // Writing to file
    fp = fopen("accounts.dat", "wb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("Enter number of bank accounts: ");
    scanf("%d", &n);
    
    printf("\nEnter bank account details:\n");
    for(i = 0; i < n; i++) {
        printf("\nAccount %d:\n", i+1);
        printf("Account Number: ");
        scanf("%ld", &acc.accountNumber);
        printf("Account Holder Name: ");
        scanf(" %[^\n]", acc.accountHolderName);
        printf("Balance: ");
        scanf("%f", &acc.balance);
        
        fwrite(&acc, sizeof(struct BankAccount), 1, fp);
    }
    
    fclose(fp);
    printf("\nBank account records saved successfully!\n");
    
    // Reading from file
    fp = fopen("accounts.dat", "rb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("\n--- Bank Account Records from File ---\n");
    i = 1;
    while(fread(&acc, sizeof(struct BankAccount), 1, fp) == 1) {
        printf("\nAccount %d:\n", i++);
        printf("Account Number: %ld\n", acc.accountNumber);
        printf("Account Holder Name: %s\n", acc.accountHolderName);
        printf("Balance: %.2f\n", acc.balance);
    }
    
    fclose(fp);
    
    return 0;
}

Sample Output: Enter number of bank accounts: 2 Enter bank account details: Account 1: Account Number: 1234567890 Account Holder Name: Robert Williams Balance: 50000 Account 2: Account Number: 9876543210 Account Holder Name: Lisa Anderson Balance: 75000 Bank account records saved successfully! --- Bank Account Records from File --- Account 1: Account Number: 1234567890 Account Holder Name: Robert Williams Balance: 50000.00 Account 2: Account Number: 9876543210 Account Holder Name: Lisa Anderson Balance: 75000.00

44. Store and read N movie details from file

#include <stdio.h>

struct Movie {
    int movieId;
    char title[100];
    int rating;
};

int main() {
    FILE *fp;
    struct Movie m;
    int n, i;
    
    // Writing to file
    fp = fopen("movies.dat", "wb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("Enter number of movies: ");
    scanf("%d", &n);
    
    printf("\nEnter movie details:\n");
    for(i = 0; i < n; i++) {
        printf("\nMovie %d:\n", i+1);
        printf("Movie ID: ");
        scanf("%d", &m.movieId);
        printf("Title: ");
        scanf(" %[^\n]", m.title);
        printf("Rating (1-10): ");
        scanf("%d", &m.rating);
        
        fwrite(&m, sizeof(struct Movie), 1, fp);
    }
    
    fclose(fp);
    printf("\nMovie records saved successfully!\n");
    
    // Reading from file
    fp = fopen("movies.dat", "rb");
    if(fp == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("\n--- Movie Records from File ---\n");
    i = 1;
    while(fread(&m, sizeof(struct Movie), 1, fp) == 1) {
        printf("\nMovie %d:\n", i++);
        printf("Movie ID: %d\n", m.movieId);
        printf("Title: %s\n", m.title);
        printf("Rating: %d/10\n", m.rating);
    }
    
    fclose(fp);
    
    return 0;
}

Sample Output: Enter number of movies: 3 Enter movie details: Movie 1: Movie ID: 301 Title: Inception Rating (1-10): 9 Movie 2: Movie ID: 302 Title: The Matrix Rating (1-10): 8 Movie 3: Movie ID: 303 Title: Interstellar Rating (1-10): 9 Movie records saved successfully! --- Movie Records from File --- Movie 1: Movie ID: 301 Title: Inception Rating: 9/10 Movie 2: Movie ID: 302 Title: The Matrix Rating: 8/10 Movie 3: Movie ID: 303 Title: Interstellar Rating: 9/10

---

Important Notes for Students:

• Make sure to understand the logic of each program before copying.
• Memory addresses in pointer programs will vary each time you run them.
• For file handling programs, ensure you have write permissions in the directory.
• Compile programs using: gcc program_name.c -o program_name
• Run programs using: ./program_name (Linux/Mac) or program_name.exe (Windows)
• Practice modifying these programs to strengthen your understanding.

C Programming Lab Solutions | Created for Educational Purposes

Happy Coding! 💻