将一个数组中的元素头尾两端对调

#include <stdio.h>

void inplace_swap(int *x, int *y) {
    printf("--------------\n");
    printf("x = %d, y = %d\n", *x, *y);
    *y = *x ^ *y;
    printf("x = %d, y = %d\n", *x, *y);
    *x = *x ^ *y;
    printf("x = %d, y = %d\n", *x, *y);
    *y = *x ^ *y;
    printf("x = %d, y = %d\n", *x, *y);
}

void reverse_array(int a[], int cnt) {
    int first, last;

    for(first=0, last=cnt-1; first<last; first++, last--) {
        inplace_swap(&a[first], &a[last]);
    }
}

int main() {
    int a[]={1,2,3,4};
    int i;

    printf("交换前: \n");

    for(i=0;i<sizeof(a)/sizeof(a[0]);i++) {
        printf("a[%d] = %d, ", i, a[i]);
    }
    printf("\n");

    reverse_array(a, sizeof(a)/sizeof(a[0]));

    printf("\n交换后: \n");

    for(i=0;i<sizeof(a)/sizeof(a[0]);i++) {
                printf("a[%d] = %d, ", i, a[i]);
        }
    printf("\n");

    return 0;
}