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0242.Valid-Anagram	https://leetcode.com/problems/valid-anagram/description/	2023-09-23 21:20:00 +0800	2023-09-23 21:20:00 +0800	false	Kimi.Tsai	https://kimi0230.github.io/	Valid Anagram			LeetCode Go Easy Valid Anagram	LeetCode			false	false	false	true	true	true	true	false	false	enable auto true true	copy maxShownLines true 200	enable		enable true	enable true	css js	images

0242.Valid-Anagram

驗證回文串

題目

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.

Example 1:

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

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

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?

我們使用 rune 數據類型來處理 Unicode 字元，並使用 map[rune]int 來統計這些字符的出現次數。其餘的邏輯保持不變。

題目大意

解題思路

只要先把所有字符轉換成小寫，並過濾掉空格和標點這類字符，然後對剩下的字符執行 數組雙指針技巧匯總 中提到的兩端向中心的雙指針演算法即可

來源

• https://leetcode.com/problems/valid-anagram/description/
• https://leetcode.cn/problems/valid-anagram/description/
• 數組雙指針技巧匯總

解答

https://github.com/kimi0230/LeetcodeGolang/blob/master/Leetcode/0242.Valid-Anagram/main.go

package validanagram

func IsAnagram(s string, t string) bool {
	if len(s) != len(t) {
		return false
	}

	record := make(map[rune]int, len(s))

	for _, v := range s {
		record[v]++
	}
	for _, v := range t {
		record[v]--
		if record[v] < 0 {
			return false
		}
	}
	return true
}

func IsAnagram2(s string, t string) bool {
	if len(s) != len(t) {
		return false
	}

	record := make(map[rune]int, len(s))

	for _, v := range s {
		record[v]++
	}
	for _, v := range t {
		record[v]--
	}

	for _, v := range record {
		if v != 0 {
			return false
		}
	}
	return true
}

Benchmark

goos: darwin
goarch: amd64
pkg: LeetcodeGolang/Leetcode/0242.Valid-Anagram
cpu: Intel(R) Core(TM) i5-8259U CPU @ 2.30GHz
BenchmarkIsAnagram-8             6703497               276.3 ns/op             0 B/op          0 allocs/op
BenchmarkIsAnagram2-8            3660909               318.9 ns/op            48 B/op          2 allocs/op
PASS
ok      LeetcodeGolang/Leetcode/0242.Valid-Anagram      4.498s