LeetCode 242. Valid Anagram（有效的字母异位词）

leetcode.com/problems/va…

Given two strings s and t, return true if t is an anagram of s, and false otherwise.

Example 1:

Input: s = "anagram", t = "nagaram"
Output: true
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Example 2:

Input: s = "rat", t = "car"
Output: false
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Constraints:

• 1 <= s.length, t.length <= 5 * 104

• s and t consist of lowercase English letters.

Follow up: What if the inputs contain Unicode characters? How would you adapt your solution to such a case?

解法一：

使用两个 Map 记录每个字符出现的次数，然后比较。

class Solution {
    fun isAnagram(s: String, t: String): Boolean {
        val sMap = mutableMapOf<Char, Int>()
        val tMap = mutableMapOf<Char, Int>()

        s.forEach {
            sMap[it] = (sMap[it] ?: 0) + 1
        }

        t.forEach {
            tMap[it] = (tMap[it] ?: 0) + 1
        }

        return sMap == tMap
    }
}
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解法二：

对两个字符串进行排序，然后比较。

class Solution {
    fun isAnagram(s: String, t: String): Boolean {
        var sList = s.toList()
        var tList = t.toList()
        
        sList = sList.sorted()
        tList = tList.sorted()

        return sList==tList
    }
}
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