Divide Two Integers(TLE)

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

class Solution {
public:
    int divide(int dividend, int divisor) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        assert(divisor);
        int ans = 0, step = 1, negative = 0,result = 0;
        if (divisor  == 1) return dividend;
        if (divisor  == -1) return -dividend;
        if (dividend == 0)  return 0;
        
        if ((dividend < 0 && divisor > 0) || (dividend > 0 && divisor < 0)) negative = 1;
        if (negative || (dividend < 0 && divisor < 0)) {
            dividend = abs(dividend);
            divisor = abs(divisor);
        }
        
        int i = 0;
        while(true){
            if (result + step * divisor > dividend){
                step >> 1;
            }
            for(int m = 0; m < step; m++){
                result += divisor;
            }
            ans += step;
            step << 1;
            i++;
        }
        while(result + divisor < dividend){
            ans++;
            result += divisor;
        }
        return negative ? -ans : ans;
    }
};

 

posted @ 2013-07-14 11:28  一只会思考的猪  阅读(208)  评论(0编辑  收藏  举报