LeetCode Flip Game

 1 public class Solution {
 2     public List<String> generatePossibleNextMoves(String s) {
 3         List<String> res = new ArrayList<String>();
 4         for(int i = 1; i<s.length(); i++){
 5             if(s.charAt(i-1) == ‘+‘ && s.charAt(i) == ‘+‘){
 6                 res.add(s.substring(0,i-1) + "--" + s.substring(i+1));
 7             }
 8         }
 9         return res;
10     }
11 }