Example: Swap Two Numbers Without using Third Variable in C language

C
C++
C#
Java
Python
PHP

// Swap Two Numbers Without using Third Variable in C language
#include <stdio.h>

int main() {
    double p, q;

    printf("----Enter the two integer or real numbers----\n");
    scanf("%lf %lf", &p, &q);

    p = p - q;
    q = p + q;
    p = q - p;

    printf("After swapping, p = %.2lf\n", p);
    printf("After swapping, q = %.2lf\n", q);
    return 0;
}