实例：将数组的头尾两端依次对调（采用异或的方法实现两数的交换，不需要临时变量）

#include <iostream>
#define N 10

void swap(int *a, int *b)  //交换a，b
{
    *a = *a ^ *b;
    *b = *a ^ *b;
    *a = *a ^ *b;
}

void reverse_arry(int a[], int arry_len) //将数组的头尾两端互换
{
    int i = 0, j = arry_len-1;
    while(i < j)
    {
        swap(&a[i], &a[j]);
        ++i;
        --j;
    }
}

int main()
{
    int a[N];
    for(int i = 0; i < N; ++i)
    {
        a[i] = i;
    }
    std::cout << "before: ";
    for(int i = 0; i < N; ++i)
    {
        std::cout << a[i] << " ";
    }
    std::cout << std::endl;

    reverse_arry(a, N);
    std::cout << "after reverse_arrt: ";
    for(int i = 0; i < N; ++i)
    {
        std::cout << a[i] << " ";
    }
    std::cout << std::endl;

}

使用异或实现两个数的交换