LeetCode: 242. Valid Anagram

题目描述

Given two strings s and t , write a function to determine if t is an anagram of s.

Example 1:

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

Example 2:

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

Note:

You may assume the string contains only lowercase alphabets.

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

Tips:
An anagram is a word or phrase formed by changing the order of the letters in another word or phrase. For example, “triangle” is an anagram of “integral.”

解题思路

将 a-z 映射到 0-25，用数组统计各单词中各字母出现的次数是否相等。若出现次数相等，则是 Anagram。否则，不是。

AC 代码

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