判断是否字母异位词-字符串

https://leetcode-cn.com/problems/valid-anagram/

思路1 统计字符数哈希表

思路2 使用数组记录出现次数

public boolean isAnagram(String s, String t) {
if (s == null || t == null) return false;
char[] schars = s.toCharArray();
char[] tchars = t.toCharArray();
if (schars.length != tchars.length) return false;

int[] counts = new int[26];
for (int i = 0; i < schars.length; i++) {
counts[schars[i] - 'a']++;
}

for (int i = 0; i < tchars.length; i++) {
if (--counts[tchars[i] - 'a'] < 0) return false;
}
return true;