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 twoconsecutive "++"
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 []
.
这道题让我们把相邻的两个 ++ 变成 –,真不是一道难题,就从第二个字母开始遍历,每次判断当前字母是否为+,和之前那个字母是否为+,如果都为加,则将翻转后的字符串存入结果中即可,参见代码如下:
class Solution {
public:
vector<string> generatePossibleNextMoves(string s) {
vector<string> res;
for (int i = 1; i < s.size(); ++i) {
if (s[i] == '+' && s[i - 1] == '+') {
res.push_back(s.substr(0, i - 1) + "--" + s.substr(i + 1));
}
}
return res;
}
};
Github 同步地址:
https://github.com/grandyang/leetcode/issues/293
类似题目:
参考资料:
https://leetcode.com/problems/flip-game/description/
https://leetcode.com/problems/flip-game/discuss/73901/4-lines-in-Java
https://leetcode.com/problems/flip-game/discuss/73902/Simple-solution-in-Java
LeetCode All in One 题目讲解汇总(持续更新中…)
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