LeetCode 29. Divide Two Integers

divide two integers without using * / and %.
the range of integer is: [-2^31, 2^31 - 1]

return integer.

class Solution {
    public int divide(int dividend, int divisor) {
        int sign = 1;
        if (dividend > 0 ^ divisor > 0) sign = -1;
        
        long ldividend = Math.abs((long) dividend);
        long ldivisor = Math.abs((long) divisor);
        
        if (dividend == 0) return 0;
        
        long lres = divide(ldividend, ldivisor);
        
        
        //do the final process to the final results
        int res = 0;
        if (lres > Integer.MAX_VALUE) {
            res = sign == 1? Integer.MAX_VALUE: Integer.MIN_VALUE;
        } else {
            res = (int) (sign * lres);
        }
        return res;
        
    }
    
    private long divide(long ldividend, long ldivisor) {
        if (ldividend < ldivisor) return 0;
        
        //core function
        long sum = ldivisor;
        long cumulative = 1;
        
        while (sum * 2 < ldividend) {
            sum = sum * 2;
            cumulative = cumulative * 2;
        }   
        return cumulative + divide(ldividend - sum, ldivisor);
    }
}