242. Valid Anagram

📋 Đề Bài

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?

🧠 Thuật Toán & Kỹ Thuật

String (Chuỗi)

⏱️ Thời gian O(n²)

💾 Không gian O(1)

💻 Lời Giải

C++ 0242-valid-anagram.cpp

class Solution {
public:
    bool isAnagram(string s, string t) {
        int cnt[26] = {0};
        for (char c : s) {
            cnt[c - 'a']++;
        }
        for (char c : t) {
            cnt[c - 'a']--;
        }
        for (int i = 0; i < 26; ++i) {
            if (cnt[i]) {
                return false;
            }
        }
        return true;
    }
};