[Leetcode] 242. Valid Anagram

題目: 242. Valid Anagram

• Given two strings s and t, return true if t is an anagram of s, and false otherwise.
• An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Input: s = "anagram", t = "nagaram"

Output: true

Example 2:

Input: s = "rat", t = "car"

Output: false

1. sorted()函數

將2個字串用sorted()進行排序，再比對是否一樣

class Solution:
    def isAnagram(self, s: str, t: str) -> bool:
        return sorted(s) == sorted(t)

2. Counter類別

s ="anagram" t ="nagaram"

Counter(s) => Counter({'a': 3, 'n': 1, 'g': 1, 'r': 1, 'm': 1})

Counter(t) => Counter({'a': 3, 'n': 1, 'g': 1, 'r': 1, 'm': 1})

class Solution:
    def isAnagram(self, s: str, t: str) -> bool:
        return Counter(s) == Counter(t)

3. Hashmap

class Solution:
    def isAnagram(self, s: str, t: str) -> bool:
        if len(s) != len(t):
            return False
        
        dicts, dictt = {},{}

        for i in range(len(s)):
            dicts[s[i]] = dicts.get(s[i],0) + 1
            dictt[t[i]] = dictt.get(t[i],0) + 1

        return dicts == dictt