使用異或交換指針的值

#include <stdio.h>
#include <stdlib.h>

void inplace_swap(int *x, int *y) {
    *y = *x ^ *y;
    *x = *x ^ *y;
    *y = *x ^ *y;
}

int main() {
    
    int x = 12;
    int y = 23;
    inplace_swap(&x, &y);
    printf("x: %d, y: %d", x, y);
    return 0;
}

對於任意位向量, 有a^a = 0

於是 *x = *x ^ (*x ^ *y ) = (*x ^ *x) ^ *y = *y

*y = *y ^ (*x ^ *y) = *x