LeetCode Divide Two Integers

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

If it is overflow, return MAX_INT.

举个例子比较容易理解，74 / 5， 这里 5*2=10 < 10*2=20 < 20*2=40 <  40*2=80，可以得到 5*8<74;然后剩下34，使用这一方法继续计算5*4=20 < 34，剩余14， 5*2<14，余下4舍去。故结果为8+4+2=14。

class Solution {
public:
int divide(int dividend, int divisor)
{
int ret = 0;
int count = 0;

long long fDivisor = divisor;
long long fDividend = dividend;
long long a = abs(fDividend);
long long b = abs(fDivisor);
long long sum = 0;
int final = 0;
bool flag = false;
if(!fDivisor || (fDividend==INT_MIN&&fDivisor==(-1))) return INT_MAX;
if(fDivisor ==0 || fDividend ==0)
return 0;

if(a  < b)
{
return 0;
}

while(a >= b)
{
int count = 1;
sum = b;
while(sum + sum < a)
{
sum += sum;
count += count;
}
a -= sum;
final += count;
}

if(fDividend * fDivisor < 0)
{
final = (-1)*final;
}
return final;
}
};