# Leecode String

###### tags: `Leetcode`

## 856. Score of Parentheses

## 22. Generate Parentheses

Time Complexity: $O(2^n)$
Space Complexity: $O(n)$

:::success
結果：Accepted
:::

class Solution:
    def generateParenthesis(self, n: int) -> List[str]:
        res = []
        
        def helper(cur, l, r):
            if l == n and r == n:
                res.append(cur)
                return
            if l < n:
                helper(cur+"(", l+1, r)
            if l > r:
                helper(cur+")", l, r+1)
        
        helper("", 0, 0)
        return res

## 49. Group Anagrams

用 sorted string 當作 key，原本的 string 當作 value，可節省查找時間

Time Complexity: $O(nmlogm)$
Space Complexity: $O(nm)$

:::success
結果：Accepted
:::

class Solution:
    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
        result = {}
        for s in strs:
            t = tuple(sorted(s))
            if t in result.keys():
                result[t].append(s)
            else:
                result[t] = [s]
        return result.values()

## 539. Minimum Time Difference

## 1156. Swap For Longest Repeated Character Substring

## 916. Word Subsets

## 583. Delete Operation for Two Strings

## 767. Reorganize String

## 1081. Smallest Subsequence of Distinct Characters

## 17. Letter Combinations of a Phone Number

## 848. Shifting Letters

## 842. Split Array into Fibonacci Sequence

## 227. Basic Calculator II