swap 2 nums without using a 3rd var.c

#include <stdio.h>

int main() {
    int a = 5, b = 7;

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

    a = a + b;
    b = a - b;
    a = a - b;

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

    return 0;
}