#include <stdio.h> void echange(int *x, int *y) { int z; z = *x; *x = *y; *y = z; } int main() { int a = 1; int b = 2; printf("a = %d; b = %d\n", a, b); echange(&a, &b); printf("a = %d; b = %d\n", a, b); return 0; }