19.swapping 2 numbers without 3rd variable using pointer.txt

#include <stdio.h>

int main() {
    int a, b;
    int *p1, *p2;

    printf("Enter the values of a and b:\n");
    scanf("%d %d", &a, &b);

    printf("Before swapping: a = %d, b = %d\n", a, b);

    p1 = &a;   // storing the address of a variable in p1
    p2 = &b;   // storing the address of b variable in p2

    *p1 = *p1 + *p2;  // adding the values stored at p1 and p2
    *p2 = *p1 - *p2;  // subtracting the value of p2 from p1 and storing it in p2
    *p1 = *p1 - *p2;  // subtracting the value of p2 from p1 and storing it in p1

    printf("After swapping: a = %d, b = %d\n", a, b);

    return 0;
}