c# Leetcode 29 (数学) 两数相除

这道题我的理解很简单，就是用相加替换乘除就可以了

可是

-2147483648
-1

测试案例不能通过

        public static int Divide(int dividend, int divisor)
        {
            int dividends = Math.Abs(dividend);
            int divisors = Math.Abs(divisor);
            int count = 1;
            int i = divisors;
            for (; i < dividends; )
               i += i;
               count++; 
             
            if(dividend > 0 && divisor < 0|| dividend < 0 && divisor > 0)
            {
                count = -count;
            }
           return count;
        }

参考下这个答案

public class Solution {
    public int Divide(int dividend, int divisor) {
        bool isPositive=true;
        if(dividend<0&&divisor>0 || dividend>0&&divisor<0){
            isPositive=false;
        }
        long ldividend = Math.Abs((long)dividend);
        long ldivisor=Math.Abs((long)divisor);
        long result=divide(ldividend,ldivisor);
        if(result>int.MaxValue){
            return isPositive?int.MaxValue:int.MinValue;
        }
        return isPositive?(int)result:-(int)result; 
    }
    public long divide(long dividend,long divisor){
        if(dividend<divisor) return 0;
        long sum=divisor;
        long result=1;
        while(dividend>sum+sum){
            sum +=sum;
            result +=result;
        }
        return result+divide(dividend-sum,divisor);
    } 
}