Question

Write C program to take four integer inputs from user (A, B, C, D) then use pointers to swap A&B, C&D. For example, if A=1, B=2, C=3, D=4, your program will return: A=2, B=1, C=4, D=3. You must use pointers for the swap.

Answer 1

#include <stdio.h>

void swap(int *p1, int *p2) {
    int temp = *p1;
    *p1 = *p2;
    *p2 = temp;
}

int main() {
    int A, B, C, D;
    printf("Enter A: ");
    scanf("%d", &A);
    printf("Enter B: ");
    scanf("%d", &B);
    printf("Enter C: ");
    scanf("%d", &C);
    printf("Enter D: ");
    scanf("%d", &D);

    // swapping A and B
    swap(&A, &B);
    // swapping C and D
    swap(&C, &D);

    printf("\nA = %d, B = %d, C = %d, D = %d\n", A, B, C, D);
    return 0;
}