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.
For example,s = "anagram", t = "nagaram", return true.s = "rat", t = "car", return 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?

原题链接

解题思路

用一个长度为26的int array来模拟hashmap
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Java代码实现

public class Solution {
    public boolean isAnagram(String s, String t) {
        if (s == null || t == null || s.length() != t.length()) {
            return false;
        }
        
        int[] arr = new int[26];
        int len = s.length();
        for (int i = 0; i < len; i++) {
            arr[s.charAt(i) - 'a'] ++;
        }
        
        for (int i = 0; i < len; i++) {
            if (--arr[t.charAt(i) - 'a'] < 0) {
                return false;
            }
        }
        
        return true;
    }
}