Divide Two Integers.2.cpp

class Solution {
public:
    int divide(int dividend, int divisor) {
        int flag=1;        int ret=0;
        if(dividend==0)return 0;
        if(divisor==INT_MIN)return dividend==INT_MIN?1:0;
        if(divisor<0){
            divisor=-divisor;
            flag*=-1;
        }
        if(dividend==INT_MIN){ret=1;dividend+=divisor;}
        if(dividend<0){
            dividend=-dividend;
            flag*=-1;
        }
        while(dividend>=divisor){
            int d=divisor,r=1;
            while(dividend-d>=d){
                d+=d;
                r+=r;
            }
            dividend-=d;
            ret+=r;
        }
        return ret*flag;
    }
};