public List<String> restoreIpAddresses(String s) {
        List<String> result = new ArrayList<>();
        List<String> current = new ArrayList<>();
        restoreIpAddressesUtil(s, 0, 0, result, current);
        return result;
    }
Date 04/04/2016
@author Tushar Roy

Given a string containing only digits, restore it by returning all possible valid IP address combinations.

Reference
https://leetcode.com/problems/restore-ip-addresses/
src/com/interview/recursion/RestoreIPAddresses.java