23.位运算实现加法

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

int add(int a, int b)
{
    int sum, jinwei;
    do
    {
        //没进位的加法结果
        sum = a^b;
        //求出总的进位
        jinwei = (a&b) << 1;
        a = sum;
        b = jinwei;
    } while (jinwei != 0);

    return sum;
}

void main()
{
    printf("%d\n", add(1, 3));

    system("pause");
}