LeetCode:29. Divide Two Integers

原创于 2019-06-21 09:25:43 发布 · 154 阅读

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博客围绕LeetCode 29题“Divide Two Integers”展开，核心是实现除法运算。采用减法来实现，在减去除数过程中动态增减除数以提高效率，还给出了Python代码实现。

LeetCode:29. Divide Two Integers

Given two integers dividend and divisor, divide two integers without using multiplication, division and mod operator.

Return the quotient after dividing dividend by divisor.

The integer division should truncate toward zero.

就是实现除法。

思路

就是用减法来实现，不断减去除数。当然为了提高效率，在减去的过程中会动态增减除数。

Python 代码实现

class Solution:
    def divide(self, dividend, divisor):
        isMinus= ((dividend<0 and divisor >0) or (dividend>0 and divisor <0));
        ret=0;        
        dividend,divisor=abs(dividend),abs(divisor);
        c,sub=1,divisor;

        while(dividend >= divisor):
            if(dividend>=sub):
                dividend-=sub;
                ret+=c;
                sub=(sub<<1);
                c=(c<<1);
            else:
                sub=(sub>>1);
                c=(c>>1);

        if(isMinus):
            ret=-ret;
        return min(max(-2147483648,ret),2147483647);