目录

位运算实现加法

位运算实现减法

位运算实现乘法

位运算实现除法

代码示例

---

PS：用位运算实现的加减乘除，其数据都是整型的(int、char、size_t等）

位运算实现加法

LeetCode_2.两数相加_小白麋鹿的博客-CSDN博客https://yt030917.blog.csdn.net/article/details/129628846

位运算实现减法

减法用加上一个数的相反数来实现

位运算实现乘法

LeetCode_面试题 08.05. 递归乘法_小白麋鹿的博客-CSDN博客https://yt030917.blog.csdn.net/article/details/129918992

位运算实现除法

LeetCode_29. 两数相除_小白麋鹿的博客-CSDN博客https://yt030917.blog.csdn.net/article/details/130753574

代码示例

class Calculate 
{
public:
    //加法
    int add(int num1, int num2) 
    {
        while (num2 != 0)
        {
            //注意这里强转是为了防止越界
            unsigned int tmp = static_cast<unsigned int>(num1 & num2) << 1;
            num1 = num1 ^ num2;
            num2 = tmp;
        }
        return num1;
    }
    //减法
    int sub(int num1, int num2) 
    {
        return add(num1, -num2);
    }
    //乘法
    int multiply(int A, int B)
    {
        int tag = A ^ B;
        int product = 0;
        A = abs(A);
        B = abs(B);
        for (int i = 0; A >> i; i++)
        {
            if ((A >> i & 1) == 1)       
                product += (long long)B << i;           
        }
        if (tag < 0)
            product = -product;
        return product;
    }
    //除法
    int divide(int dividend, int divisor)
    {
        if (dividend == INT_MIN && divisor == INT_MIN)    
            return 1;        
        else if (divisor == INT_MIN)
            return 0;

        if (dividend == INT_MIN)
        {
            if (divisor == -1)
                return INT_MAX;
            else if (divisor == 1)
                return INT_MIN;

            int tmp = div(dividend + 1, divisor);
            return tmp + div(dividend - multiply(tmp, divisor), divisor);
        }
        //以上部分均为处理INT_MIN的特殊情况
        return div(dividend, divisor);
    }
private:
    int div(int dividend, int divisor)
    {
        int tag = dividend ^ divisor;
        dividend = dividend > 0 ? dividend : ~dividend + 1;
        divisor = divisor > 0 ? divisor : ~divisor + 1;
        int ans = 0;
        while (dividend >= divisor)
        {
            int index = -1;
            while (dividend >> ++index >= divisor);
            index--;
            dividend -= divisor << index;
            ans |= 1 << index;
        }
        if (tag < 0)
            ans = -ans;
        return ans;
    }

};