By Siyu Lei

29. Divide Two Integers.java

class Solution {
    public int divide(int dividend, int divisor) {
        if (dividend == Integer.MIN_VALUE && divisor == -1) {
            return Integer.MAX_VALUE;
        }
        boolean sign = (dividend > 0) ^ (divisor > 0);
        long dvd = Math.abs((long) dividend);
        long dvs = Math.abs((long) divisor);
        int res = 0;
        while (dvd >= dvs) {
            long temp = dvs;
            int multiple = 1;
            while (dvd >= (temp << 1)) {
                multiple <<= 1;
                temp <<= 1;
            }
            dvd -= temp;
            res += multiple;
        }
        return sign ? -res : res;
    }
}