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 []
.
1 class Solution {
2 public:
3 vector<string> generatePossibleNextMoves(string s) {
4 vector<string> res;
5 for (int i = 0, n = s.size() - 1; i < n; i++)
6 if (s[i] == '+' && s[i + 1] == '+') {
7 string temp = s;
8 temp[i] = temp[i + 1] = '-';
9 res.push_back(temp);
10 }
11 return res;
12 }
13 };