leetcode242. Valid Anagram

242. Valid Anagram

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.

解法一

字典序排序。然后逐个判断

public class Solution {
    public boolean isAnagram(String s, String t) {
        if (s.length() != t.length()) {
            return false;
        }

        char[] sChar = s.toCharArray();
        char[] tChar = t.toCharArray();
        Arrays.sort(sChar);
        Arrays.sort(tChar);
        for (int i = 0; i < sChar.length; i++) {
            if (sChar[i] != tChar[i]) {
                return false;
            }
        }

        return true;
    }
}

解法二

一个数组存放每个字符出现的个数。

public class Solution {
    public boolean isAnagram(String s, String t) {
        if (s.length() != t.length()) {
            return false;
        }
        int[] count = new int[256];
        char[] sChar = s.toCharArray();
        char[] tChar = t.toCharArray();
        for (int i = 0; i < sChar.length; i++) {
            count[sChar[i] - 'a']++;
            count[tChar[i] - 'a']--;
        }

        for (int c : count) {
            if (c != 0) {
                return false;
            }
        }

        return true;
    }
}