Divide Two Integers

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

If it is overflow, return MAX_INT.

 

public class Solution {
    public static long divide(int dividend, int divisor) {
    	int sign;
    	int res = 0;
        if (dividend<0 && divisor<0 || dividend>0 && divisor>0) {
        	sign = 1;
        } else if (dividend == 0) {
        	return 0;
        } else if (divisor == 0) {
        	throw new RuntimeException("divisor is 0");
        } else if (dividend>Integer.MAX_VALUE || divisor>Integer.MAX_VALUE || dividend<Integer.MIN_VALUE || divisor<Integer.MIN_VALUE) {
        	return Integer.MAX_VALUE;
        }
        else {
        	sign = -1;
        }
        long newdividend = Math.abs((long)dividend);
        long newdivisor = Math.abs((long)divisor);
        int digit = 0;
        while ((newdivisor<<digit) <= newdividend) {
        	digit++;
        }
        long temp = newdividend;
        for (int i = digit-1; i >= 0; i--) {
        	long t = newdivisor << i;
        	if (temp < t) {
        		continue;
        	}
        	temp -= t;
        	if (i == 0) {
        		res += 1;
        	} else {
        		res += 2<<(i-1);
        		if (res <= Integer.MIN_VALUE && sign==1) {
                    return Integer.MAX_VALUE;
                }
        	}
        }
        if (sign == -1) {
        	return  -res;
        }
        return  res;
    }
}