C Programming

In C programming, structures provide a way to group related data under a single name. Here’s an example of a C program that creates a structure for representing student details.

In C programming, a pointer is a variable that stores the memory address of another variable. Pointers are powerful and flexible features in C, allowing direct manipulation of memory and providing a way to implement dynamic memory allocation. Here are some key concepts related to pointers: Pointers require careful use to avoid common pitfalls like segmentation faults and undefined behavior. Memory management and pointer arithmetic should be done with caution to ensure the stability and correctness of your programs. Program : #include<stdio.h>#include<conio.h>main(){int a;int *pointer=&a;printf(“Enter the value of a : “);scanf(“%d”,&a);printf(“\nThe value of a is : %d”,a);printf(“\nThe address of a is : %x”,&a);printf(“\nThe value of pointer is : %x”,pointer);printf(“\nThe address of pointer is : %x”,&pointer);getch();} Output :

Below is a simple C program that checks whether an input character is a digit, alphabet, or a special character.

A palindrome is a string that reads the same forward and backward. Here’s a simple C program that checks whether a given string is a palindrome or not.

An Armstrong number (also known as a narcissistic number, pluperfect number, or pluperfect digital invariant) is a number that is the sum of its own digits each raised to the power of the number of digits. For example, 153 is an Armstrong number . Here’s a simple C program to check if a given number is an Armstrong number: Program : #include<stdio.h>#include<conio.h>void main(){int a,n,b=0,t;printf(“Enter the number : “);scanf(“%d”,&n);t=n;while(n>0){a=n%10;b=b+a*a*a;n=n/10;}if(b==t){printf(“%d is a Armstrong Number.”,t);}else{printf(“%d is not an Armstrong Number.”,t);}} Output :

Below is a simple C program that creates a menu-driven program to implement matrix addition, subtraction, and multiplication. This program assumes that the matrices are square matrices of the same size for addition and subtraction, and suitable for matrix multiplication. Program : #include<stdio.h> #include<conio.h>   int sum(int x[100][100], int y[100][100], int result[100][100], int v, int q) { int i,j; for(i=0;i<v;i++)     for(j=0;j<q;j++)     result[i][j] = x[i][j] + y[i][j]; } int sub(int x[100][100], int y[100][100], int result[100][100], int v, int q) { int i,j; for(i=0;i<v;i++)     for(j=0;j<q;j++)     result[i][j] = x[i][j] – y[i][j]; } int mul(int x[100][100], int y[100][100], int result[100][100], int v, int q) { int i,j; for(i=0;i<v;i++)     for(j=0;j<q;j++)     result[i][j] = x[i][j] * y[i][j]; } void display(int matrix[100][100], int v, int q) { int i,j;   for( i=0; i<v; i++)   {     for( j=0; j<q; j++)       printf(“%d\t”,matrix[i][j]);       printf(“\n”);   } } int main() {   int r, c, d[100][100], a[100][100], b[100][100], e[100][100], i, j, z, choice;   printf(“Enter the number of rows (between 1 and 100): “);   scanf(“%d”, &r);   printf(“Enter the number of columns (between 1 and 100): “);   scanf(“%d”, &c);     printf(“\nEnter elements of 1st matrix:\n”);   for (i = 0; i < r; ++i)   {     for (j = 0; j < c; ++j)  {       printf(“Enter element a%d%d: “, i + 1, j + 1);       scanf(“%d”, &a[i][j]);     }   }     printf(“Enter elements of 2nd matrix:\n”);   for (i = 0; i < r; ++i)   {     for (j = 0; j < c; ++j)  {       printf(“Enter element b%d%d: “, i + 1, j + 1);       scanf(“%d”, &b[i][j]);     }   }     printf(“\nChoose the matrix operation,\n”);     printf(“—————————-\n”);     printf(“1. Addition\n”);     printf(“2. Subtraction\n”);     printf(“3. Multiplication\n”);     printf(“—————————-\n”);     printf(“Enter your choice: “);     scanf(“%d”, &choice);       switch (choice) {       case 1:         sum(a, b, d, r, c);         printf(“Sum of matrix: \n”);         display(d, r, c);         break;       case 2:         sub(a, b, d, r, c);         printf(“Subtraction of matrix: \n”);         display(d, r, c);         break;       case 3:         mul(a, b, d, r, c);         printf(“Multiplication of matrix: \n”);         display(d, r, c);         break;       default:         printf(“Invalid input.\n”);         printf(“Please enter the correct input.\n”);    } } Output :

Below is a simple C program that counts the occurrences of each element in an array. This program takes an array as input from the user, counts the occurrences of each element, and then prints the count for each unique element in the array. It uses a nested loop to iterate through the array and count occurrences. Program : #include <stdio.h>int main(){int arr[100], freq[100];int size, i, j, count;printf(“Enter size of array: “);scanf(“%d”, &size);printf(“Enter elements in array: “);for(i=0; i<size; i++){scanf(“%d”, &arr[i]);freq[i] = -1;}for(i=0; i<size; i++){count = 1;for(j=i+1; j<size; j++){if(arr[i]==arr[j]){count++;freq[j] = 0;}}if(freq[i] != 0){freq[i] = count;}}printf(“\nFrequency of all elements of array : \n”);for(i=0; i<size; i++){if(freq[i] != 0){printf(“%d occurs %d times\n”, arr[i], freq[i]);}}return 0;} Output :

Below is a simple C program that searches for an element in an array and prints the index if the element is found or a message indicating that the element is not present .

To find duplicate elements in an array using a C program,you can use nested loops or hash sets. I’ll provide you with a simple example using nested loops. Here’s a sample program. Program : #include<stdio.h>#include<conio.h> void main(){int i,arr[20],j,no; printf(“Enter size of array: “);scanf(“%d”,&no);printf(“Enter any %d elements in array: “,no);for(i=0;i<no;i++){scanf(“%d”,&arr[i]);}printf(“Duplicate elements are: “);for(i=0; i<no; i++){for(j=i+1;j<no;j++){if(arr[i]==arr[j]){printf(“%d\n”,arr[i]);}}}getch();} Output :

Reversing an array in C involves swapping the elements of the array in a way that the first element becomes the last, the second becomes the second-to-last, and so on. Here’s a simple C program that reverses an array Program : #include<stdio.h>void main(){int i,length;printf(“Enter the Length of array : “);scanf(“%d”,&length);int arr[length];printf(“Enter elements into the array:”);for(i=0;i<length;i++){printf(“arr[%d] :”,i);scanf(“%d”,&arr[i]);}printf(“\nOriginal array: \n”); for ( i = 0; i < length; i++) { printf(“%d “, arr[i]); } printf(“\nArray in reverse order: \n”); for ( i = length-1; i >= 0; i–) { printf(“%d “, arr[i]); } return 0; } Output :