Divide Two Integers

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

If it is overflow, return MAX_INT.

Tag: 二分求解，相当于每次除数都乘以2，注意考虑负数的情况和整数溢出的情况。

int divide(int dividend, int divisor){const int MAX_INT = (unsigned)(-1)>>1;const int MIN_INT = (unsigned)(~MAX_INT);if(dividend == divisor) return 1;if(divisor == 0 || (dividend == MIN_INT && divisor == -1)) return MAX_INT;if(divisor == MIN_INT) return 0;if(divisor == 1) return dividend;if(divisor == -1) return -dividend;bool negtive = (dividend < 0) ^ (divisor < 0);long _dividend, _divisor;if(dividend < 0){if(dividend == MIN_INT)_dividend = (long) MAX_INT + 1l;else_dividend = -dividend;}else{_dividend = dividend;}_divisor = (divisor < 0) ? -divisor : divisor;int result = 0;while(_divisor <= _dividend){int ans = 1;long div_tmp = _divisor;while(_dividend >> 1 >= div_tmp){ans <<= 1;div_tmp <<= 1;}result += ans;_dividend -= div_tmp;}return (negtive) ? -result : result;}