_293.java

package com.fishercoder.solutions;

import java.util.ArrayList;
import java.util.List;
/**
 * 293. Flip Game
 *
 * You are playing the following Flip Game with your friend: Given a string that contains only
 * these two characters: + and -, you and your friend take turns to flip two consecutive "++" into "--".
 * The game ends when a person can no longer make a move and therefore the other person will be the winner.
 Write a function to compute all possible states of the string after one valid move.
 For example, given s = "++++", after one move, it may become one of the following states:

 [
 "--++",
 "+--+",
 "++--"
 ]
 If there is no valid move, return an empty list [].*/
public class _293 {

    public static class Solutoin1 {
        public List<String> generatePossibleNextMoves(String s) {
            List<String> result = new ArrayList<>();
            for (int i = 1; i < s.length(); i++) {
                if (s.charAt(i) == '+' && s.charAt(i - 1) == '+') {
                    result.add(s.substring(0, i - 1) + "--" + s.substring(i + 1));
                }
            }
            return result;
        }
    }
}