使用位操作符计算两个整数的平均数，不会发生溢出

average.cpp内容如下:

#include <iostream>
using namespace std;

int average(int a, int b)
{
    return (a & b) + ((a ^ b) >> 1);
}

int main(int argc, char** argv)
{
    int a = 123456789;
    int b = 23456789;
    cout << "average of " << a << " and " << b << " is: " << average(a, b) << endl;

    return 0;
}

运行结果如下：