Divide Two Integers

题目描述：

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

If it is overflow, return INT_MAX.

　　提示中谈到Binary Search，由此可想到解决方案。

solution：

int divide(int dividend, int divisor) {
    if(divisor == 0)
        return INT_MAX;
    if(dividend == INT_MIN && divisor == -1)
        return INT_MAX;

    int sign = (dividend > 0 ^ divisor > 0) ? -1 : 1;
    long long end = abs( (long long)dividend);
    long long sor = abs( (long long)divisor);
    long long res = 0;
    
    while (end >= sor)
    {
        long long tmp = sor;
        long long power = 1;
        while ( (tmp << 1) < end)
        {
            power <<= 1;
            tmp <<= 1;
        }
        res += power;
        end -= tmp;
    }
    return sign > 0 ? res : -res;
}

参考资料：https://leetcode.com/discuss/11358/simple-o-log-n-2-c-solution

转载于:https://www.cnblogs.com/gattaca/p/4581825.html