C Programming Codes

#include <stdio.h>

struct Date {
    int day;
    int month;
    int year;
};

struct Student {
    char name[50];
    int rollNumber;
    struct Date birthday;
};

int main() {
    struct Student student1;

    printf("Enter student name: ");
    scanf("%s", student1.name);

    printf("Enter roll number: ");
    scanf("%d", &student1.rollNumber);

    printf("Enter birthday (day month year): ");
    scanf("%d %d %d", &student1.birthday.day, &student1.birthday.month, &student1.birthday.year);

    printf("nStudent Details:n");
    printf("Name: %sn", student1.name);
    printf("Roll Number: %dn", student1.rollNumber);
    printf("Birthday: %d/%d/%dn", student1.birthday.day, student1.birthday.month, student1.birthday.year);

    return 0;
}

Input: JohnDoe
Input: 123
Input: 15 08 2000
Output: Enter student name: Enter roll number: Enter birthday (day month year):
Student Details:
Name: JohnDoe
Roll Number: 123
Birthday: 15/8/2000

#include <stdio.h>
#define PI 3.14159

struct Circle {
    float radius;
};

int main() {
    struct Circle myCircle;

    printf("Enter the radius of the circle: ");
    scanf("%f", &myCircle.radius);

    float area = PI * myCircle.radius * myCircle.radius;
    float circumference = 2 * PI * myCircle.radius;

    printf("Area of the circle: %.2fn", area);
    printf("Circumference of the circle: %.2fn", circumference);

    return 0;
}

Input: 5
Output: Enter the radius of the circle: Area of the circle: 78.54
Circumference of the circle: 31.42

#include <stdio.h>

struct Rectangle {
    float length;
    float width;
};

int main() {
    struct Rectangle myRectangle;

    printf("Enter the length of the rectangle: ");
    scanf("%f", &myRectangle.length);

    printf("Enter the width of the rectangle: ");
    scanf("%f", &myRectangle.width);

    float area = myRectangle.length * myRectangle.width;
    float perimeter = 2 * (myRectangle.length + myRectangle.width);

    printf("Area of the rectangle: %.2fn", area);
    printf("Perimeter of the rectangle: %.2fn", perimeter);

    return 0;
}

Input: 5.0
Input: 3.0
Output: Area of the rectangle: 15.00
Output: Perimeter of the rectangle: 16.00

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

struct Account {
    int accountNumber;
    char accountHolderName[50];
    float balance;
};

int main() {
    struct Account myAccount;

    printf("Enter account number: ");
    scanf("%d", &myAccount.accountNumber);

    printf("Enter account holder name: ");
    scanf(" %[^n]s", myAccount.accountHolderName);

    printf("Enter initial balance: ");
    scanf("%f", &myAccount.balance);

    printf("nAccount Details:n");
    printf("Account Number: %dn", myAccount.accountNumber);
    printf("Account Holder Name: %sn", myAccount.accountHolderName);
    printf("Balance: %.2fn", myAccount.balance);

    float depositAmount;
    printf("nEnter amount to deposit: ");
    scanf("%f", &depositAmount);
    myAccount.balance += depositAmount;
    printf("New balance after deposit: %.2fn", myAccount.balance);

    float withdrawalAmount;
    printf("nEnter amount to withdraw: ");
    scanf("%f", &withdrawalAmount);
    if (withdrawalAmount <= myAccount.balance) {
        myAccount.balance -= withdrawalAmount;
        printf("New balance after withdrawal: %.2fn", myAccount.balance);
    } else {
        printf("Insufficient balance.n");
    }

    return 0;
}

Input: 12345
Input: John Doe
Input: 1000.00
Output: Enter account number: Enter account holder name: Enter initial balance:
Account Details:
Account Number: 12345
Account Holder Name: John Doe
Balance: 1000.00
Enter amount to deposit: Input: 500.00
Output: New balance after deposit: 1500.00
Enter amount to withdraw: Input: 200.00
Output: New balance after withdrawal: 1300.00

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

struct Book {
    char title[50];
    char author[50];
    int book_id;
};

int main() {
    struct Book book1;

    printf("Enter book title: ");
    scanf(" %[^n]s", book1.title);

    printf("Enter author name: ");
    scanf(" %[^n]s", book1.author);

    printf("Enter book ID: ");
    scanf("%d", &book1.book_id);

    printf("nBook Details:n");
    printf("Title: %sn", book1.title);
    printf("Author: %sn", book1.author);
    printf("Book ID: %dn", book1.book_id);

    return 0;
}

Input: The Lord of the Rings
Input: J.R.R. Tolkien
Input: 12345
Output: Enter book title: Enter author name: Enter book ID:
Book Details:
Title: The Lord of the Rings
Author: J.R.R. Tolkien
Book ID: 12345

#include <stdio.h>
#include <stdbool.h>

typedef struct {
    int day;
    int month;
    int year;
} Date;

bool isValidDate(Date date) {
    if (date.year < 1 || date.month < 1 || date.month > 12 || date.day < 1) {
        return false;
    }

    int daysInMonth[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

    if ((date.year % 4 == 0 && date.year % 100 != 0) || (date.year % 400 == 0)) {
        daysInMonth[2] = 29;
    }

    if (date.day > daysInMonth[date.month]) {
        return false;
    }

    return true;
}

Date addDays(Date date, int daysToAdd) {
    Date newDate = date;
    int daysInMonth[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

    if ((newDate.year % 4 == 0 && newDate.year % 100 != 0) || (newDate.year % 400 == 0)) {
        daysInMonth[2] = 29;
    }

    newDate.day += daysToAdd;

    while (newDate.day > daysInMonth[newDate.month]) {
        newDate.day -= daysInMonth[newDate.month];
        newDate.month++;
        if (newDate.month > 12) {
            newDate.month = 1;
            newDate.year++;
            if ((newDate.year % 4 == 0 && newDate.year % 100 != 0) || (newDate.year % 400 == 0)) {
                daysInMonth[2] = 29;
            } else {
                daysInMonth[2] = 28;
            }
        }
    }

    return newDate;
}

int main() {
    Date myDate;
    int daysToAdd;

    printf("Enter date (day month year): ");
    scanf("%d %d %d", &myDate.day, &myDate.month, &myDate.year);

    if (!isValidDate(myDate)) {
        printf("Invalid date!n");
        return 1;
    }

    printf("Enter number of days to add: ");
    scanf("%d", &daysToAdd);

    Date newDate = addDays(myDate, daysToAdd);

    printf("New date: %d/%d/%dn", newDate.day, newDate.month, newDate.year);

    return 0;
}

Input: 28 2 2023
Output: Enter date (day month year): Enter number of days to add: 5
New date: 5/3/2023
Input: 31 12 2023
Output: Enter date (day month year): Enter number of days to add: 1
New date: 1/1/2024
Input: 29 2 2024
Output: Enter date (day month year): Enter number of days to add: 1
New date: 1/3/2024
Input: 1 1 2024
Output: Enter date (day month year): Enter number of days to add: 366
New date: 1/1/2025
Input: 31 4 2023
Output: Enter date (day month year): Invalid date!

#include <stdio.h>

struct Time {
    int hours;
    int minutes;
    int seconds;
};

int main() {
    struct Time t1, t2, sum, diff;

    printf("Enter first time (hours minutes seconds): ");
    scanf("%d %d %d", &t1.hours, &t1.minutes, &t1.seconds);

    printf("Enter second time (hours minutes seconds): ");
    scanf("%d %d %d", &t2.hours, &t2.minutes, &t2.seconds);

    // Time Addition
    sum.seconds = t1.seconds + t2.seconds;
    sum.minutes = t1.minutes + t2.minutes + sum.seconds / 60;
    sum.hours = t1.hours + t2.hours + sum.minutes / 60;

    sum.minutes %= 60;
    sum.seconds %= 60;
    sum.hours %= 24;

    printf("Sum of times: %d:%d:%dn", sum.hours, sum.minutes, sum.seconds);

    // Time Subtraction (t1 - t2)
    int t1_sec = t1.hours * 3600 + t1.minutes * 60 + t1.seconds;
    int t2_sec = t2.hours * 3600 + t2.minutes * 60 + t2.seconds;
    int diff_sec = t1_sec - t2_sec;

    if (diff_sec < 0) {
        diff_sec = -diff_sec; //absolute difference
    }

    diff.hours = diff_sec / 3600;
    diff.minutes = (diff_sec % 3600) / 60;
    diff.seconds = (diff_sec % 3600) % 60;

    printf("Difference of times: %d:%d:%dn", diff.hours, diff.minutes, diff.seconds);

    return 0;
}

Input: 10 30 45
Input: 5 15 20
Output: Sum of times: 15:46:5
Output: Difference of times: 5:15:25

#include <stdio.h>
#include <math.h>

struct Point {
    float x;
    float y;
};

int main() {
    struct Point p1, p2;
    float distance;

    printf("Enter x and y coordinates for point 1: ");
    scanf("%f %f", &p1.x, &p1.y);

    printf("Enter x and y coordinates for point 2: ");
    scanf("%f %f", &p2.x, &p2.y);

    distance = sqrt(pow(p2.x - p1.x, 2) + pow(p2.y - p1.y, 2));

    printf("Distance between the two points: %fn", distance);

    return 0;
}

Input: 1.0 2.0
Input: 4.0 6.0
Output: Distance between the two points: 5.000000

#include <stdio.h>

typedef struct {
    float real;
    float imaginary;
} Complex;

Complex add(Complex a, Complex b) {
    Complex result;
    result.real = a.real + b.real;
    result.imaginary = a.imaginary + b.imaginary;
    return result;
}

Complex subtract(Complex a, Complex b) {
    Complex result;
    result.real = a.real - b.real;
    result.imaginary = a.imaginary - b.imaginary;
    return result;
}

int main() {
    Complex num1, num2, sum, difference;

    printf("Enter real and imaginary parts of first complex number: ");
    scanf("%f %f", &num1.real, &num1.imaginary);

    printf("Enter real and imaginary parts of second complex number: ");
    scanf("%f %f", &num2.real, &num2.imaginary);

    sum = add(num1, num2);
    printf("Sum = %.2f + %.2fin", sum.real, sum.imaginary);

    difference = subtract(num1, num2);
    printf("Difference = %.2f + %.2fin", difference.real, difference.imaginary);

    return 0;
}

Input: 3.4 5.2
Input: -1.1 2.5
Output: Enter real and imaginary parts of first complex number: Enter real and imaginary parts of second complex number: Sum = 2.30 + 7.70i
Output: Difference = 4.50 + 2.70i

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

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

int main() {
    struct Employee emp;

    printf("Enter employee ID: ");
    scanf("%d", &emp.id);
    printf("Enter employee name: ");
    scanf(" %[^n]s", emp.name);
    printf("Enter employee salary: ");
    scanf("%f", &emp.salary);

    printf("nEmployee Details:n");
    printf("ID: %dn", emp.id);
    printf("Name: %sn", emp.name);
    printf("Salary: %.2fn", emp.salary);

    return 0;
}

Input: 123
Input: John Doe
Input: 60000.50
Output: Enter employee ID: Enter employee name: Enter employee salary:
Employee Details:
ID: 123
Name: John Doe
Salary: 60000.50

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

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

int main() {
    struct Student student1;

    printf("Enter student name: ");
    scanf("%s", student1.name);

    printf("Enter roll number: ");
    scanf("%d", &student1.rollNumber);

    printf("Enter marks: ");
    scanf("%f", &student1.marks);

    printf("nStudent Details:n");
    printf("Name: %sn", student1.name);
    printf("Roll Number: %dn", student1.rollNumber);
    printf("Marks: %.2fn", student1.marks);

    return 0;
}

Input: John
Input: 123
Input: 85.5
Output: Enter student name: Enter roll number: Enter marks:
Student Details:
Name: John
Roll Number: 123
Marks: 85.50

#include <stdio.h>
#include <stdlib.h>

struct Student {
    int id;
    char name[50];
    float gpa;
};

int main() {
    int n;

    printf("Enter the number of students: ");
    scanf("%d", &n);

    struct Student *students[n]; // Array of structure pointers

    // Allocate memory for each student and get input
    for (int i = 0; i < n; i++) {
        students[i] = (struct Student*)malloc(sizeof(struct Student));

        printf("Enter details for student %d:n", i + 1);

        printf("ID: ");
        scanf("%d", &(students[i]->id));

        printf("Name: ");
        scanf(" %[^n]", students[i]->name); // Read name with spaces

        printf("GPA: ");
        scanf("%f", &(students[i]->gpa));
    }

    // Print the student details
    printf("nStudent Details:n");
    for (int i = 0; i < n; i++) {
        printf("Student %d:n", i + 1);
        printf("ID: %dn", students[i]->id);
        printf("Name: %sn", students[i]->name);
        printf("GPA: %.2fn", students[i]->gpa);
    }

    // Free the allocated memory
    for (int i = 0; i < n; i++) {
        free(students[i]);
    }

    return 0;
}

Input: 2
Input: 123
Input: Alice Smith
Input: 3.85
Input: 456
Input: Bob Johnson
Input: 3.5

Output:
Enter the number of students: Enter details for student 1:
ID: Name: GPA: Enter details for student 2:
ID: Name: GPA:
Student Details:
Student 1:
ID: 123
Name: Alice Smith
GPA: 3.85
Student 2:
ID: 456
Name: Bob Johnson
GPA: 3.50

#include <stdio.h>
#include <stdlib.h>

struct Person {
    char name[50];
    int age;
};

int main() {
    struct Person person1;
    struct Person *ptrPerson;

    ptrPerson = &person1;

    printf("Enter name: ");
    scanf("%s", ptrPerson->name);

    printf("Enter age: ");
    scanf("%d", &ptrPerson->age);

    printf("Name: %sn", ptrPerson->name);
    printf("Age: %dn", ptrPerson->age);

    return 0;
}

Input: John
Input: 30
Output: Enter name: Enter age: Name: John
Age: 30

#include <stdio.h>
#include <stdlib.h>

int main() {
    int *ptr;

    ptr = (int *)malloc(sizeof(int));

    if (ptr == NULL) {
        printf("Memory allocation failed!n");
        return 1;
    }

    printf("Enter an integer value: ");
    scanf("%d", ptr);

    printf("You entered: %dn", *ptr);

    free(ptr);

    ptr = NULL;

    return 0;
}

Input: 10
Output: Enter an integer value: You entered: 10

#include <stdio.h>
#include <stdlib.h>

int main() {
    int *arr;
    int size, new_size, i;

    printf("Enter the initial size of the array: ");
    scanf("%d", &size);

    arr = (int *)malloc(size * sizeof(int));

    if (arr == NULL) {
        printf("Memory allocation failed.n");
        return 1;
    }

    printf("Enter %d elements:n", size);
    for (i = 0; i < size; i++) {
        scanf("%d", &arr[i]);
    }

    printf("Enter the new size of the array: ");
    scanf("%d", &new_size);

    arr = (int *)realloc(arr, new_size * sizeof(int));

    if (arr == NULL) {
        printf("Memory reallocation failed.n");
        return 1;
    }

    printf("Memory reallocated successfully.n");

    if (new_size > size) {
        printf("Enter the remaining %d elements:n", new_size - size);
        for (i = size; i < new_size; i++) {
            scanf("%d", &arr[i]);
        }
    }

    printf("Elements of the array:n");
    for (i = 0; i < new_size; i++) {
        printf("%d ", arr[i]);
    }
    printf("n");

    free(arr);

    return 0;
}

Input: 3
Output: Enter the initial size of the array:
Input: 1
Output: Enter 3 elements:
Input: 2
Output:
Input: 3
Output: Enter the new size of the array:
Input: 5
Output: Memory reallocated successfully.
Output: Enter the remaining 2 elements:
Input: 4
Output:
Input: 5
Output: Elements of the array:
Output: 1 2 3 4 5

#include <stdio.h>
#include <stdlib.h>

int main() {
    int *arr_malloc, *arr_calloc;
    int n, i;

    printf("Enter the number of elements: ");
    scanf("%d", &n);

    arr_malloc = (int*) malloc(n * sizeof(int));
    if (arr_malloc == NULL) {
        printf("Memory allocation failed using malloc!n");
        return 1;
    }

    printf("Memory allocated successfully using malloc.n");

    printf("Enter elements for malloc array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr_malloc[i]);
    }

    printf("Elements in malloc array:n");
    for (i = 0; i < n; i++) {
        printf("%d ", arr_malloc[i]);
    }
    printf("n");

    arr_calloc = (int*) calloc(n, sizeof(int));
    if (arr_calloc == NULL) {
        printf("Memory allocation failed using calloc!n");
        free(arr_malloc);
        return 1;
    }

    printf("Memory allocated successfully using calloc. Initialized to 0.n");

    printf("Enter elements for calloc array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr_calloc[i]);
    }

    printf("Elements in calloc array:n");
    for (i = 0; i < n; i++) {
        printf("%d ", arr_calloc[i]);
    }
    printf("n");

    free(arr_malloc);
    free(arr_calloc);

    return 0;
}

Input: 3
Output: Enter the number of elements: Memory allocated successfully using malloc.
Enter elements for malloc array:
Input: 10
Input: 20
Input: 30
Output: Elements in malloc array:
10 20 30
Output: Memory allocated successfully using calloc. Initialized to 0.
Enter elements for calloc array:
Input: 40
Input: 50
Input: 60
Output: Elements in calloc array:
40 50 60

#include <stdio.h>

int add(int a, int b) {
  return a + b;
}

int subtract(int a, int b) {
  return a - b;
}

int main() {
  int x, y, choice, result;
  int (*operation)(int, int);

  printf("Enter two numbers: ");
  scanf("%d %d", &x, &y);

  printf("Choose an operation:n");
  printf("1. Addn");
  printf("2. Subtractn");
  printf("Enter your choice (1 or 2): ");
  scanf("%d", &choice);

  if (choice == 1) {
    operation = add;
  } else if (choice == 2) {
    operation = subtract;
  } else {
    printf("Invalid choice.n");
    return 1;
  }

  result = operation(x, y);

  printf("Result: %dn", result);

  return 0;
}

Input: 5 3
Input: 1
Output: Enter two numbers: Choose an operation:
1. Add
2. Subtract
Enter your choice (1 or 2): Result: 8

Input: 10 4
Input: 2
Output: Enter two numbers: Choose an operation:
1. Add
2. Subtract
Enter your choice (1 or 2): Result: 6

Input: 2 7
Input: 3
Output: Enter two numbers: Choose an operation:
1. Add
2. Subtract
Enter your choice (1 or 2): Invalid choice.

#include <stdio.h>

int add(int a, int b) {
  return a + b;
}

int subtract(int a, int b) {
  return a - b;
}

int main() {
  int x, y, choice, result;
  int (*operation)(int, int);

  printf("Enter two integers: ");
  scanf("%d %d", &x, &y);

  printf("Choose an operation:n");
  printf("1. Addn");
  printf("2. Subtractn");
  printf("Enter your choice (1 or 2): ");
  scanf("%d", &choice);

  if (choice == 1) {
    operation = add;
  } else if (choice == 2) {
    operation = subtract;
  } else {
    printf("Invalid choice.n");
    return 1; // Indicate an error
  }

  result = operation(x, y);

  printf("Result: %dn", result);

  return 0;
}

Input: 5 3
Input: 1
Output: Enter two integers: Choose an operation:
1. Add
2. Subtract
Enter your choice (1 or 2): Result: 8

Input: 10 4
Input: 2
Output: Enter two integers: Choose an operation:
1. Add
2. Subtract
Enter your choice (1 or 2): Result: 6

Input: 2 7
Input: 3
Output: Enter two integers: Choose an operation:
1. Add
2. Subtract
Enter your choice (1 or 2): Invalid choice.

#include <stdio.h>

int main() {
    int num = 10;
    int *ptr = &num;
    int **ptr_to_ptr = &ptr;

    printf("Value of num: %dn", num);
    printf("Address of num: %pn", (void*)&num);

    printf("Value of ptr: %pn", (void*)ptr);
    printf("Address of ptr: %pn", (void*)&ptr);
    printf("Value pointed to by ptr: %dn", *ptr);

    printf("Value of ptr_to_ptr: %pn", (void*)ptr_to_ptr);
    printf("Address of ptr_to_ptr: %pn", (void*)&ptr_to_ptr);
    printf("Value pointed to by ptr_to_ptr: %pn", (void*)*ptr_to_ptr);
    printf("Value pointed to by *ptr_to_ptr: %dn", **ptr_to_ptr);

    return 0;
}

Value of num: 10
Address of num: 0x7ffc75467b18
Value of ptr: 0x7ffc75467b18
Address of ptr: 0x7ffc75467b20
Value pointed to by ptr: 10
Value of ptr_to_ptr: 0x7ffc75467b20
Address of ptr_to_ptr: 0x7ffc75467b28
Value pointed to by ptr_to_ptr: 0x7ffc75467b18
Value pointed to by *ptr_to_ptr: 10