EasyNo. 0293LeetCode Premium
Flip Game — LeetCode 293 Python Solution
- Pattern
- Hash Map
- Topics
- String
- Reading time
- 2 min
- Source
- leetcode.com
The problem
You are playing a Flip Game with your friend. You are given a string currentState that contains only '+' and '-'.
Example
- Input
- currentState = "++++"
- Output
- ["--++","+--+","++--"]
Python solution
class Solution:
def generatePossibleNextMoves(self, currentState: str) -> List[str]:
s = list(currentState)
ans = []
for i, (a, b) in enumerate(pairwise(s)):
if a == b == "+":
s[i] = s[i + 1] = "-"
ans.append("".join(s))
s[i] = s[i + 1] = "+"
return ansComplexity
- Time
- O(n2)where n is the length of the string
- Space · auxiliary
- O(n) or O(1)
Pattern: Hash Map
Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 293. Flip Game is filed here because the reference solution below belongs to the algorithm family this hub collects, even though its LeetCode tags point elsewhere.
The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.
Related problems
| No. | Problem | Difficulty |
|---|---|---|
| 0006 | Zigzag Conversion | Medium |
| 0008 | String to Integer (atoi) | Medium |
| 0038 | Count and Say | Medium |
| 0058 | Length of Last Word | Easy |
| 0065 | Valid Number | Hard |
| 0068 | Text Justification | Hard |
Frequently asked questions
- How hard is LeetCode 293. Flip Game?
LeetCode 293. Flip Game is rated Easy on LeetCode.
- What topics does LeetCode 293. Flip Game cover?
LeetCode 293. Flip Game is tagged String on LeetCode.
- Is LeetCode 293. Flip Game a premium problem?
Yes. LeetCode 293. Flip Game is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.