LeetCode(29):Divide Two Integers

Divide Two Integers:Divide two integers without using multiplication, division and mod operator.

If it is overflow, return MAX_INT.

题意：实现整数的除法，不能使用/运算符。

思路：参考http://blog.csdn.net/linhuanmars/article/details/20024907?utm_source=tuicool&utm_medium=referral

代码：

public class Solution {
    public int divide(int dividend, int divisor) {
        if(dividend == 0) { return 0;}
        boolean isNeg = (dividend^divisor)>>>31 == 1;
        int res = 0;
        if(dividend == Integer.MIN_VALUE){
            dividend += Math.abs(divisor);
            if(divisor==-1){
                return Integer.MAX_VALUE;
            }
            res++;
        }
        if(divisor==Integer.MIN_VALUE){
            return res;
        }
        dividend = Math.abs(dividend);
        divisor = Math.abs(divisor);
        int digit = 0;
        while(divisor<= (dividend>>1)){
            divisor<<=1;
            digit++;
        }
        while(digit>=0){
            if(dividend >= divisor){
                res += 1<<digit;
                dividend -= divisor;
            }
            divisor >>=1;
            digit--;
        }
        return isNeg ? -res:res;
    }
    
}