Saturday, January 18, 2025 02:03:42 AM
Top 50 C Programs
hello_world.c
// 1. hello_world.c
#include <stdio.h>
int main() {
// Print "Hello, World!" to the console
printf("Hello, World!\n");
return 0;
}
Last Modified: January 12, 2025 19:05:29
sum_of_two_numbers.c
// 2. sum_of_two_numbers.c
#include <stdio.h>
int main() {
int a, b, sum;
// Input two integers
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
// Calculate sum
sum = a + b;
printf("Sum: %d\n", sum);
return 0;
}
Last Modified: January 12, 2025 19:05:54
difference_of_two_numbers.c
// 3. difference_of_two_numbers.c
#include <stdio.h>
int main() {
int a, b, difference;
// Input two integers
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
// Calculate difference
difference = a - b;
printf("Difference: %d\n", difference);
return 0;
}
Last Modified: January 12, 2025 19:06:17
multiplication_of_two_numbers.c
// 4. multiplication_of_two_numbers.c
#include <stdio.h>
int main() {
int a, b, product;
// Input two integers
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
// Calculate product
product = a * b;
printf("Product: %d\n", product);
return 0;
}
Last Modified: January 12, 2025 19:08:16
division_of_two_numbers.c
// 5. division_of_two_numbers.c
#include <stdio.h>
int main() {
int a, b;
float result;
// Input two integers
printf("Enter two integers (dividend and divisor): ");
scanf("%d %d", &a, &b);
// Check for division by zero
if (b != 0) {
result = (float)a / b;
printf("Result: %.2f\n", result);
} else {
printf("Error: Division by zero is not allowed.\n");
}
return 0;
}
Last Modified: January 12, 2025 19:08:37
swap_two_numbers_with_variable.c
// 6. swap_two_numbers_with_variable.c
#include <stdio.h>
int main() {
int a, b, temp;
// Input two integers
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
// Swap using a temporary variable
temp = a;
a = b;
b = temp;
printf("After swapping: a = %d, b = %d\n", a, b);
return 0;
}
Last Modified: January 12, 2025 19:09:07
swap_two_numbers_without_variable.c
// 7. swap_two_numbers_without_variable.c
#include <stdio.h>
int main() {
int a, b;
// Input two integers
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
// Swap without a temporary variable
a = a + b;
b = a - b;
a = a - b;
printf("After swapping: a = %d, b = %d\n", a, b);
return 0;
}
Last Modified: January 12, 2025 19:10:27
check_even_or_odd.c
// 8. check_even_or_odd.c
#include <stdio.h>
int main() {
int num;
// Input an integer
printf("Enter an integer: ");
scanf("%d", &num);
// Check if the number is even or odd
if (num % 2 == 0) {
printf("%d is even.\n", num);
} else {
printf("%d is odd.\n", num);
}
return 0;
}
Last Modified: January 12, 2025 19:10:48
largest_of_two_numbers.c
// 9. largest_of_two_numbers.c
#include <stdio.h>
int main() {
int a, b;
// Input two integers
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
// Find the largest number
if (a > b) {
printf("%d is larger.\n", a);
} else if (b > a) {
printf("%d is larger.\n", b);
} else {
printf("Both numbers are equal.\n");
}
return 0;
}
Last Modified: January 12, 2025 19:11:09
largest_of_three_numbers.c
// 10. largest_of_three_numbers.c
#include <stdio.h>
int main() {
int a, b, c;
// Input three integers
printf("Enter three integers: ");
scanf("%d %d %d", &a, &b, &c);
// Find the largest number
if (a >= b && a >= c) {
printf("%d is the largest.\n", a);
} else if (b >= a && b >= c) {
printf("%d is the largest.\n", b);
} else {
printf("%d is the largest.\n", c);
}
return 0;
}
Last Modified: January 12, 2025 19:11:30
check_prime_number.c
// 11. check_prime_number.c
#include <stdio.h>
int main() {
int num, i, is_prime = 1;
// Input an integer
printf("Enter an integer: ");
scanf("%d", &num);
if (num <= 1) {
printf("%d is not a prime number.\n", num);
return 0;
}
// Check divisors from 2 to sqrt(num)
for (i = 2; i * i <= num; i++) {
if (num % i == 0) {
is_prime = 0;
break;
}
}
if (is_prime) {
printf("%d is a prime number.\n", num);
} else {
printf("%d is not a prime number.\n", num);
}
return 0;
}
Last Modified: January 12, 2025 19:11:51
print_numbers_from_1_to_n.c
// 1. print_numbers_from_1_to_n.c
#include <stdio.h>
int main() {
int n;
// Input the value of N
printf("Enter a number: ");
scanf("%d", &n);
printf("Numbers from 1 to %d:\n", n);
for (int i = 1; i <= n; i++) {
printf("%d ", i);
}
printf("\n");
return 0;
}
Last Modified: January 12, 2025 19:15:17
print_multiplication_table.c
// 2. print_multiplication_table.c
#include <stdio.h>
int main() {
int num;
// Input the number for multiplication table
printf("Enter a number: ");
scanf("%d", &num);
printf("Multiplication table of %d:\n", num);
for (int i = 1; i <= 10; i++) {
printf("%d x %d = %d\n", num, i, num * i);
}
return 0;
}
Last Modified: January 12, 2025 19:15:44
sum_of_first_n_natural_numbers.c
// 3. sum_of_first_n_natural_numbers.c
#include <stdio.h>
int main() {
int n, sum = 0;
// Input the value of N
printf("Enter a number: ");
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
sum += i;
}
printf("Sum of first %d natural numbers is %d\n", n, sum);
return 0;
}
Last Modified: January 12, 2025 19:16:03
reverse_a_number.c
// 4. reverse_a_number.c
#include <stdio.h>
int main() {
int num, reversed = 0;
// Input a number
printf("Enter a number: ");
scanf("%d", &num);
while (num != 0) {
reversed = reversed * 10 + num % 10;
num /= 10;
}
printf("Reversed number is %d\n", reversed);
return 0;
}
Last Modified: January 12, 2025 19:16:24
count_digits_in_a_number.c
// 5. count_digits_in_a_number.c
#include <stdio.h>
int main() {
int num, count = 0;
// Input a number
printf("Enter a number: ");
scanf("%d", &num);
do {
count++;
num /= 10;
} while (num != 0);
printf("Number of digits: %d\n", count);
return 0;
}
Last Modified: January 12, 2025 19:17:11
palindrome_number.c
// 6. palindrome_number.c
#include <stdio.h>
int main() {
int num, reversed = 0, original;
// Input a number
printf("Enter a number: ");
scanf("%d", &num);
original = num;
while (num != 0) {
reversed = reversed * 10 + num % 10;
num /= 10;
}
if (original == reversed) {
printf("%d is a palindrome.\n", original);
} else {
printf("%d is not a palindrome.\n", original);
}
return 0;
}
Last Modified: January 12, 2025 19:17:35
armstrong_number.c
#include <stdio.h>
#include <math.h>
int main() {
int num, original, remainder, n = 0;
double result = 0.0;
// Input a number
printf("Enter a number: ");
scanf("%d", &num);
original = num;
while (original != 0) {
original /= 10;
n++;
}
original = num;
while (original != 0) {
remainder = original % 10;
result += pow(remainder, n);
original /= 10;
}
if ((int)result == num) {
printf("%d is an Armstrong number.\n", num);
} else {
printf("%d is not an Armstrong number.\n", num);
}
return 0;
}
Last Modified: January 12, 2025 19:18:02
fibonacci_series.c
// 8. fibonacci_series.c
#include <stdio.h>
int main() {
int n, t1 = 0, t2 = 1, nextTerm;
// Input the number of terms
printf("Enter the number of terms: ");
scanf("%d", &n);
printf("Fibonacci Series: %d, %d", t1, t2);
for (int i = 3; i <= n; i++) {
nextTerm = t1 + t2;
printf(", %d", nextTerm);
t1 = t2;
t2 = nextTerm;
}
printf("\n");
return 0;
}
Last Modified: January 12, 2025 19:18:24
factorial_of_a_number.c
// 9. factorial_of_a_number.c
#include <stdio.h>
// Function to calculate factorial using recursion
int factorial_recursive(int n) {
if (n == 0 || n == 1) {
return 1;
}
return n * factorial_recursive(n - 1);
}
// Function to calculate factorial using iteration
int factorial_iterative(int n) {
int fact = 1;
for (int i = 1; i <= n; i++) {
fact *= i;
}
return fact;
}
int main() {
int n;
// Input a number
printf("Enter a number: ");
scanf("%d", &n);
printf("Factorial (Recursive): %d\n", factorial_recursive(n));
printf("Factorial (Iterative): %d\n", factorial_iterative(n));
return 0;
}
Last Modified: January 12, 2025 19:19:11
sum_of_digits_in_a_number.c
// 10. sum_of_digits_in_a_number.c
#include <stdio.h>
int main() {
int num, sum = 0;
// Input a number
printf("Enter a number: ");
scanf("%d", &num);
while (num != 0) {
sum += num % 10;
num /= 10;
}
printf("Sum of digits: %d\n", sum);
return 0;
}
Last Modified: January 12, 2025 19:19:29
find_largest_element_in_array.c
#include <stdio.h>
int main() {
int n, i, largest;
printf("Enter the number of elements: ");
scanf("%d", &n);
int arr[n];
printf("Enter the elements: ");
for (i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
largest = arr[0]; // Assume the first element is the largest
for (i = 1; i < n; i++) {
if (arr[i] > largest) {
largest = arr[i]; // Update largest if current element is larger
}
}
printf("The largest element in the array is: %d\n", largest);
return 0;
}
Last Modified: January 12, 2025 19:22:46
reverse_array.c
#include <stdio.h>
int main() {
int n, i;
printf("Enter the number of elements: ");
scanf("%d", &n);
int arr[n], reversed[n];
printf("Enter the elements: ");
for (i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
// Reversing the array
for (i = 0; i < n; i++) {
reversed[i] = arr[n - 1 - i];
}
printf("Reversed array: ");
for (i = 0; i < n; i++) {
printf("%d ", reversed[i]);
}
printf("\n");
return 0;
}
Last Modified: January 12, 2025 19:23:04
bubble_sort.c
#include <stdio.h>
int main() {
int n, i, j, temp;
printf("Enter the number of elements: ");
scanf("%d", &n);
int arr[n];
printf("Enter the elements: ");
for (i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
// Bubble sort algorithm
for (i = 0; i < n - 1; i++) {
for (j = 0; j < n - i - 1; j++) {
if (arr[j] > arr[j + 1]) {
// Swap arr[j] and arr[j+1]
temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
}
printf("Sorted array (Bubble Sort): ");
for (i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
return 0;
}
Last Modified: January 12, 2025 19:23:20
selection_sort.c
#include <stdio.h>
int main() {
int n, i, j, minIdx, temp;
printf("Enter the number of elements: ");
scanf("%d", &n);
int arr[n];
printf("Enter the elements: ");
for (i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
// Selection sort algorithm
for (i = 0; i < n - 1; i++) {
minIdx = i;
for (j = i + 1; j < n; j++) {
if (arr[j] < arr[minIdx]) {
minIdx = j;
}
}
// Swap the found minimum element with the first element
temp = arr[i];
arr[i] = arr[minIdx];
arr[minIdx] = temp;
}
printf("Sorted array (Selection Sort): ");
for (i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
return 0;
}
Last Modified: January 12, 2025 19:23:40
linear_search.c
#include <stdio.h>
int main() {
int n, key, i, found = 0;
printf("Enter the number of elements: ");
scanf("%d", &n);
int arr[n];
printf("Enter the elements: ");
for (i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
printf("Enter the element to search: ");
scanf("%d", &key);
// Linear search algorithm
for (i = 0; i < n; i++) {
if (arr[i] == key) {
found = 1;
break;
}
}
if (found) {
printf("Element found at index %d\n", i);
} else {
printf("Element not found\n");
}
return 0;
}
Last Modified: January 12, 2025 19:24:03
binary_search.c
#include <stdio.h>
int binary_search(int arr[], int n, int key) {
int left = 0, right = n - 1, mid;
while (left <= right) {
mid = (left + right) / 2;
if (arr[mid] == key) {
return mid;
} else if (arr[mid] < key) {
left = mid + 1;
} else {
right = mid - 1;
}
}
return -1;
}
int main() {
int n, key, result;
printf("Enter the number of elements: ");
scanf("%d", &n);
int arr[n];
printf("Enter the sorted elements: ");
for (int i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
printf("Enter the element to search: ");
scanf("%d", &key);
result = binary_search(arr, n, key);
if (result != -1) {
printf("Element found at index %d\n", result);
} else {
printf("Element not found\n");
}
return 0;
}
Last Modified: January 12, 2025 19:24:13
matrix_addition.c
#include <stdio.h>
int main() {
int i, j, row, col;
printf("Enter number of rows and columns: ");
scanf("%d %d", &row, &col);
int A[row][col], B[row][col], sum[row][col];
printf("Enter elements of matrix A:\n");
for (i = 0; i < row; i++) {
for (j = 0; j < col; j++) {
scanf("%d", &A[i][j]);
}
}
printf("Enter elements of matrix B:\n");
for (i = 0; i < row; i++) {
for (j = 0; j < col; j++) {
scanf("%d", &B[i][j]);
}
}
// Matrix addition
for (i = 0; i < row; i++) {
for (j = 0; j < col; j++) {
sum[i][j] = A[i][j] + B[i][j];
}
}
printf("Resultant matrix (A + B):\n");
for (i = 0; i < row; i++) {
for (j = 0; j < col; j++) {
printf("%d ", sum[i][j]);
}
printf("\n");
}
return 0;
}
Last Modified: January 12, 2025 19:24:30
matrix_multiplication.c
#include <stdio.h>
int main() {
int i, j, k, row1, col1, row2, col2;
printf("Enter number of rows and columns for matrix A: ");
scanf("%d %d", &row1, &col1);
printf("Enter number of rows and columns for matrix B: ");
scanf("%d %d", &row2, &col2);
if (col1 != row2) {
printf("Matrix multiplication not possible\n");
return 0;
}
int A[row1][col1], B[row2][col2], product[row1][col2];
printf("Enter elements of matrix A:\n");
for (i = 0; i < row1; i++) {
for (j = 0; j < col1; j++) {
scanf("%d", &A[i][j]);
}
}
printf("Enter elements of matrix B:\n");
for (i = 0; i < row2; i++) {
for (j = 0; j < col2; j++) {
scanf("%d", &B[i][j]);
}
}
// Matrix multiplication
for (i = 0; i < row1; i++) {
for (j = 0; j < col2; j++) {
product[i][j] = 0;
for (k = 0; k < col1; k++) {
product[i][j] += A[i][k] * B[k][j];
}
}
}
printf("Resultant matrix (A * B):\n");
for (i = 0; i < row1; i++) {
for (j = 0; j < col2; j++) {
printf("%d ", product[i][j]);
}
printf("\n");
}
return 0;
}
Last Modified: January 12, 2025 19:24:52
check_palindrome.c
#include <stdio.h>
#include <string.h>
int main() {
char str[100];
int i, len, isPalindrome = 1;
printf("Enter a string: ");
scanf("%s", str);
len = strlen(str);
for (i = 0; i < len / 2; i++) {
if (str[i] != str[len - i - 1]) {
isPalindrome = 0;
break;
}
}
if (isPalindrome) {
printf("The string is a palindrome\n");
} else {
printf("The string is not a palindrome\n");
}
return 0;
}
Last Modified: January 12, 2025 19:25:08
reverse_string.c
#include <stdio.h>
#include <string.h>
int main() {
char str[100], reversed[100];
int i, len;
printf("Enter a string: ");
scanf("%s", str);
len = strlen(str);
for (i = 0; i < len; i++) {
reversed[i] = str[len - i - 1];
}
reversed[len] = '\0'; // Null terminate the string
printf("Reversed string: %s\n", reversed);
return 0;
}
Last Modified: January 12, 2025 19:25:33
count_vowels_consonants.c
#include <stdio.h>
#include <ctype.h>
int main() {
char str[100];
int vowels = 0, consonants = 0, i;
printf("Enter a string: ");
fgets(str, sizeof(str), stdin);
for (i = 0; str[i] != '\0'; i++) {
if (isalpha(str[i])) {
switch (tolower(str[i])) {
case 'a':
case 'e':
case 'i':
case 'o':
case 'u':
vowels++;
break;
default:
consonants++;
break;
}
}
}
printf("Vowels: %d, Consonants: %d\n", vowels, consonants);
return 0;
}
Last Modified: January 12, 2025 19:25:43
find_gcd_of_two_numbers.c
#include <stdio.h>
int gcd(int a, int b) {
// Using Euclidean algorithm to find GCD
if (b == 0)
return a;
return gcd(b, a % b);
}
int main() {
int a, b;
printf("Enter two numbers: ");
scanf("%d %d", &a, &b);
printf("The GCD of %d and %d is: %d\n", a, b, gcd(a, b));
return 0;
}
Last Modified: January 12, 2025 19:27:19
find_lcm_of_two_numbers.c
#include <stdio.h>
int gcd(int a, int b) {
if (b == 0)
return a;
return gcd(b, a % b);
}
int lcm(int a, int b) {
return (a * b) / gcd(a, b);
}
int main() {
int a, b;
printf("Enter two numbers: ");
scanf("%d %d", &a, &b);
printf("The LCM of %d and %d is: %d\n", a, b, lcm(a, b));
return 0;
}
Last Modified: January 12, 2025 19:27:35
generate_pascals_triangle.c
#include <stdio.h>
void printPascal(int n) {
int i, j, num = 1;
for (i = 0; i < n; i++) {
num = 1;
for (j = 0; j < (n - i - 1); j++) {
printf(" "); // Print leading spaces
}
for (j = 0; j <= i; j++) {
printf("%d ", num);
num = num * (i - j) / (j + 1);
}
printf("\n");
}
}
int main() {
int n;
printf("Enter the number of rows: ");
scanf("%d", &n);
printPascal(n);
return 0;
}
Last Modified: January 12, 2025 19:27:52
tower_of_hanoi.c
#include <stdio.h>
void towerOfHanoi(int n, char from, char to, char aux) {
if (n == 1) {
printf("Move disk 1 from %c to %c\n", from, to);
return;
}
towerOfHanoi(n - 1, from, aux, to);
printf("Move disk %d from %c to %c\n", n, from, to);
towerOfHanoi(n - 1, aux, to, from);
}
int main() {
int n;
printf("Enter the number of disks: ");
scanf("%d", &n);
towerOfHanoi(n, 'A', 'C', 'B'); // A is source, C is destination, B is auxiliary
return 0;
}
Last Modified: January 12, 2025 19:28:09
calculate_power_using_recursion.c
#include <stdio.h>
int power(int base, int exp) {
if (exp == 0) {
return 1;
}
return base * power(base, exp - 1); // Recursively multiply the base
}
int main() {
int base, exp;
printf("Enter base and exponent: ");
scanf("%d %d", &base, &exp);
printf("%d raised to the power %d is: %d\n", base, exp, power(base, exp));
return 0;
}
Last Modified: January 12, 2025 19:28:30
check_armstrong_number_using_functions.c
#include <stdio.h>
#include <math.h>
int isArmstrong(int num) {
int sum = 0, temp = num, digit, n = 0;
// Count number of digits in num
while (temp != 0) {
n++;
temp /= 10;
}
temp = num;
// Calculate sum of powers of digits
while (temp != 0) {
digit = temp % 10;
sum += pow(digit, n);
temp /= 10;
}
return sum == num;
}
int main() {
int num;
printf("Enter a number: ");
scanf("%d", &num);
if (isArmstrong(num)) {
printf("%d is an Armstrong number\n", num);
} else {
printf("%d is not an Armstrong number\n", num);
}
return 0;
}
Last Modified: January 12, 2025 19:28:47
swap_two_numbers_using_pointers.c
#include <stdio.h>
void swap(int *a, int *b) {
int temp = *a;
*a = *b;
*b = temp;
}
int main() {
int x, y;
printf("Enter two numbers: ");
scanf("%d %d", &x, &y);
printf("Before swapping: x = %d, y = %d\n", x, y);
swap(&x, &y);
printf("After swapping: x = %d, y = %d\n", x, y);
return 0;
}
Last Modified: January 12, 2025 19:29:11
reverse_array_using_pointers.c
#include <stdio.h>
void reverseArray(int *arr, int size) {
int *start = arr;
int *end = arr + size - 1;
int temp;
while (start < end) {
temp = *start;
*start = *end;
*end = temp;
start++;
end--;
}
}
int main() {
int n;
printf("Enter the number of elements: ");
scanf("%d", &n);
int arr[n];
printf("Enter the elements: ");
for (int i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
reverseArray(arr, n);
printf("Reversed array: ");
for (int i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
return 0;
}
Last Modified: January 12, 2025 19:29:22
dynamic_memory_allocation_malloc_calloc_free.c
#include <stdio.h>
#include <stdlib.h>
int main() {
int n;
printf("Enter the number of elements: ");
scanf("%d", &n);
// Dynamic memory allocation using malloc
int *arr = (int *)malloc(n * sizeof(int));
if (arr == NULL) {
printf("Memory allocation failed!\n");
return 1;
}
printf("Enter the elements: ");
for (int i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
printf("Entered elements: ");
for (int i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
// Free dynamically allocated memory
free(arr);
return 0;
}
Last Modified: January 12, 2025 19:29:42
pointer_to_a_function_example.c
#include <stdio.h>
int add(int a, int b) {
return a + b;
}
int subtract(int a, int b) {
return a - b;
}
int main() {
int (*funcPtr)(int, int); // Function pointer declaration
int num1, num2, result;
printf("Enter two numbers: ");
scanf("%d %d", &num1, &num2);
// Pointing to add function
funcPtr = &add;
result = funcPtr(num1, num2);
printf("Addition: %d\n", result);
// Pointing to subtract function
funcPtr = &subtract;
result = funcPtr(num1, num2);
printf("Subtraction: %d\n", result);
return 0;
}
Last Modified: January 12, 2025 19:29:58
read_from_a_file.c
#include <stdio.h>
int main() {
FILE *file;
char ch;
file = fopen("example.txt", "r");
if (file == NULL) {
printf("Error opening file.\n");
return 1;
}
printf("Contents of the file:\n");
while ((ch = fgetc(file)) != EOF) {
putchar(ch); // Print each character
}
fclose(file);
return 0;
}
Last Modified: January 12, 2025 19:31:42
write_to_a_file.c
#include <stdio.h>
int main() {
FILE *file;
char str[] = "Hello, this is a test message written to a file.";
file = fopen("example.txt", "w");
if (file == NULL) {
printf("Error opening file.\n");
return 1;
}
fprintf(file, "%s\n", str);
printf("Data successfully written to file.\n");
fclose(file);
return 0;
}
Last Modified: January 12, 2025 19:31:58
copy_a_file.c
#include <stdio.h>
int main() {
FILE *source, *destination;
char ch;
source = fopen("source.txt", "r");
if (source == NULL) {
printf("Error opening source file.\n");
return 1;
}
destination = fopen("destination.txt", "w");
if (destination == NULL) {
printf("Error opening destination file.\n");
fclose(source);
return 1;
}
while ((ch = fgetc(source)) != EOF) {
fputc(ch, destination);
}
printf("File copied successfully.\n");
fclose(source);
fclose(destination);
return 0;
}
Last Modified: January 12, 2025 19:32:15
append_data_to_a_file.c
#include <stdio.h>
int main() {
FILE *file;
char str[] = "This is an appended line of text.";
file = fopen("example.txt", "a");
if (file == NULL) {
printf("Error opening file.\n");
return 1;
}
fprintf(file, "%s\n", str);
printf("Data successfully appended to file.\n");
fclose(file);
return 0;
}
Last Modified: January 12, 2025 19:32:31
count_words_in_a_file.c
#include <stdio.h>
#include <ctype.h>
int main() {
FILE *file;
char ch;
int words = 0;
int in_word = 0;
file = fopen("example.txt", "r");
if (file == NULL) {
printf("Error opening file.\n");
return 1;
}
while ((ch = fgetc(file)) != EOF) {
if (isspace(ch)) {
in_word = 0;
} else if (in_word == 0) {
in_word = 1;
words++;
}
}
printf("Word count: %d\n", words);
fclose(file);
return 0;
}
Last Modified: January 12, 2025 19:32:49
implement_a_linked_list_singly.c
#include <stdio.h>
#include <stdlib.h>
struct Node {
int data;
struct Node *next;
};
void printList(struct Node *head) {
struct Node *temp = head;
while (temp != NULL) {
printf("%d -> ", temp->data);
temp = temp->next;
}
printf("NULL\n");
}
int main() {
struct Node *head = NULL;
struct Node *second = NULL;
struct Node *third = NULL;
head = (struct Node *)malloc(sizeof(struct Node));
second = (struct Node *)malloc(sizeof(struct Node));
third = (struct Node *)malloc(sizeof(struct Node));
head->data = 1;
head->next = second;
second->data = 2;
second->next = third;
third->data = 3;
third->next = NULL;
printf("Linked List: ");
printList(head);
return 0;
}
Last Modified: January 12, 2025 19:33:11
implement_a_linked_list_doubly.c
#include <stdio.h>
#include <stdlib.h>
struct Node {
int data;
struct Node *prev;
struct Node *next;
};
void printList(struct Node *head) {
struct Node *temp = head;
while (temp != NULL) {
printf("%d <-> ", temp->data);
temp = temp->next;
}
printf("NULL\n");
}
int main() {
struct Node *head = NULL;
struct Node *second = NULL;
struct Node *third = NULL;
head = (struct Node *)malloc(sizeof(struct Node));
second = (struct Node *)malloc(sizeof(struct Node));
third = (struct Node *)malloc(sizeof(struct Node));
head->data = 1;
head->prev = NULL;
head->next = second;
second->data = 2;
second->prev = head;
second->next = third;
third->data = 3;
third->prev = second;
third->next = NULL;
printf("Doubly Linked List: ");
printList(head);
return 0;
}
Last Modified: January 12, 2025 19:33:50
implement_a_stack_using_arrays.c
#include <stdio.h>
#define MAX 5
int stack[MAX];
int top = -1;
int isFull() {
return top == MAX - 1;
}
int isEmpty() {
return top == -1;
}
void push(int value) {
if (isFull()) {
printf("Stack Overflow\n");
} else {
stack[++top] = value;
printf("%d pushed to stack\n", value);
}
}
int pop() {
if (isEmpty()) {
printf("Stack Underflow\n");
return -1;
} else {
return stack[top--];
}
}
int peek() {
if (isEmpty()) {
printf("Stack is empty\n");
return -1;
} else {
return stack[top];
}
}
int main() {
push(10);
push(20);
push(30);
printf("Top element is: %d\n", peek());
printf("%d popped from stack\n", pop());
printf("Top element is now: %d\n", peek());
return 0;
}
Last Modified: January 12, 2025 19:34:09
implement_a_queue_using_arrays.c
#include <stdio.h>
#define MAX 5
int queue[MAX];
int front = -1, rear = -1;
int isFull() {
return (rear + 1) % MAX == front;
}
int isEmpty() {
return front == -1;
}
void enqueue(int value) {
if (isFull()) {
printf("Queue Overflow\n");
} else {
if (front == -1) {
front = 0;
}
rear = (rear + 1) % MAX;
queue[rear] = value;
printf("%d enqueued to queue\n", value);
}
}
int dequeue() {
if (isEmpty()) {
printf("Queue Underflow\n");
return -1;
} else {
int item = queue[front];
if (front == rear) {
front = rear = -1;
} else {
front = (front + 1) % MAX;
}
return item;
}
}
int main() {
enqueue(10);
enqueue(20);
enqueue(30);
printf("%d dequeued from queue\n", dequeue());
printf("%d dequeued from queue\n", dequeue());
return 0;
}
Last Modified: January 12, 2025 19:34:26
binary_search_tree_operations.c
#include <stdio.h>
#include <stdlib.h>
struct Node {
int data;
struct Node *left, *right;
};
struct Node* newNode(int data) {
struct Node* node = (struct Node*)malloc(sizeof(struct Node));
node->data = data;
node->left = node->right = NULL;
return node;
}
struct Node* insert(struct Node* root, int data) {
if (root == NULL)
return newNode(data);
if (data < root->data)
root->left = insert(root->left, data);
else
root->right = insert(root->right, data);
return root;
}
struct Node* minValueNode(struct Node* node) {
struct Node* current = node;
while (current && current->left != NULL)
current = current->left;
return current;
}
struct Node* deleteNode(struct Node* root, int key) {
if (root == NULL)
return root;
if (key < root->data)
root->left = deleteNode(root->left, key);
else if (key > root->data)
root->right = deleteNode(root->right, key);
else {
if (root->left == NULL) {
struct Node* temp = root->right;
free(root);
return temp;
} else if (root->right == NULL) {
struct Node* temp = root->left;
free(root);
return temp;
}
struct Node* temp = minValueNode(root->right);
root->data = temp->data;
root->right = deleteNode(root->right, temp->data);
}
return root;
}
void inorder(struct Node* root) {
if (root != NULL) {
inorder(root->left);
printf("%d ", root->data);
inorder(root->right);
}
}
int main() {
struct Node* root = NULL;
root = insert(root, 50);
root = insert(root, 30);
root = insert(root, 20);
root = insert(root, 40);
root = insert(root, 70);
root = insert(root, 60);
root = insert(root, 80);
printf("Inorder traversal: ");
inorder(root);
printf("\n");
root = deleteNode(root, 20);
printf("Inorder traversal after deletion: ");
inorder(root);
printf("\n");
return 0;
}
Last Modified: January 12, 2025 19:34:44
dijkstras_algorithm.c
#include <stdio.h>
#include <limits.h>
#define V 9
int minDistance(int dist[], int sptSet[]) {
int min = INT_MAX, min_index;
for (int v = 0; v < V; v++) {
if (sptSet[v] == 0 && dist[v] <= min) {
min = dist[v];
min_index = v;
}
}
return min_index;
}
void dijkstra(int graph[V][V], int src) {
int dist[V];
int sptSet[V]; // Shortest Path Tree Set
for (int i = 0; i < V; i++) {
dist[i] = INT_MAX;
sptSet[i] = 0;
}
dist[src] = 0;
for (int count = 0; count < V - 1; count++) {
int u = minDistance(dist, sptSet);
sptSet[u] = 1;
for (int v = 0; v < V; v++) {
if (!sptSet[v] && graph[u][v] && dist[u] != INT_MAX && dist[u] + graph[u][v] < dist[v]) {
dist[v] = dist[u] + graph[u][v];
}
}
}
printf("Vertex\tDistance from Source\n");
for (int i = 0; i < V; i++) {
printf("%d\t%d\n", i, dist[i]);
}
}
int main() {
int graph[V][V] = { {0, 4, 0, 0, 0, 0, 0, 8, 0},
{4, 0, 8, 0, 0, 0, 0, 11, 0},
{0, 8, 0, 7, 0, 4, 0, 0, 2},
{0, 0, 7, 0, 9, 14, 0, 0, 0},
{0, 0, 0, 9, 0, 10, 0, 0, 0},
{0, 0, 4, 14, 10, 0, 2, 0, 0},
{0, 0, 0, 0, 0, 2, 0, 1, 6},
{8, 11, 0, 0, 0, 0, 1, 0, 7},
{0, 0, 2, 0, 0, 0, 6, 7, 0} };
dijkstra(graph, 0); // Starting from vertex 0
return 0;
}
Last Modified: January 12, 2025 19:35:08