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 [].
Solution:
class Solution(object):
def generatePossibleNextMoves(self, s):
"""
:type s: str
:rtype: List[str]
"""
result = []
pre = ''
for idx, cur in enumerate(s):
if cur == pre == '+':
result.append('{}{}{}'.format(s[:idx - 1], '--', s[idx + 1:]))
pre = cur
return result