Divide Two Integers

class Solution {
public:
    int divide(int dividend, int divisor) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if (divisor == 0)
            return INT_MAX;
            
        bool negative = (dividend > 0) == (divisor > 0) ? false: true;
        
    	unsigned int copyed_value = dividend;
        unsigned int absDividend = (copyed_value > 0x80000000) ? -dividend : copyed_value;
		copyed_value = divisor; 
        long long absDivisor = (copyed_value > 0x80000000) ? -divisor : copyed_value;
        
        int result=divideHelp(absDividend,absDivisor);
        return negative? -result : result;
    }
    
    unsigned int divideHelp(unsigned int dividend, unsigned int divisor){
        int result = 0;
        while (dividend >= divisor){
            unsigned int divisortemp = divisor;
            int tempresult = 1;
			
            while( (divisortemp <= (INT_MAX/2+1)) && (dividend > divisortemp + divisortemp)){
                tempresult <<= 1;
                divisortemp += divisortemp;
            }
            
            if (tempresult > 1){
                result +=tempresult;
                dividend -= divisortemp;
            }
            if (dividend >= divisor){
                result +=1;
                dividend -= divisor;
            }
        }
        
        return result;
    }
};

1. 如何取绝对值

2. while 循环里对

divisortemp + divisortemp

的divisortemp的溢出判断

3. 第一个while循环里的 >= , 以及里面最后一个 if （dividend >= divisor）的 位置