package normal;

import java.util.HashMap;

/**

* @program JavaBooks

* @description: 242.有效的字母异位词

* @author: mf

* @create: 2019/11/06 15:19

*/

/*

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

类型：哈希等

难度：easy

*/

/*

输入: s = "anagram", t = "nagaram"

输出: true

输入: s = "rat", t = "car"

输出: false

*/

public class IsAnagram {

public static void main(String[] args) {

String s = "anagram";

String t = "nagaram";

System.out.println(isAnagram(s, t));

System.out.println(isAnagram2(s, t));

}

/**

* 普通字符串方法

* @param s

* @param t

* @return

*/

private static boolean isAnagram(String s, String t) {

int[] sCount = new int[26];

int[] tCount = new int[26];

for (char ch : s.toCharArray()) {

sCount[ch - 'a']++;

}

for (char c : t.toCharArray()) {

tCount[c - 'a']++;

}

for (int i = 0; i < 26; i++) {

if (sCount[i] != tCount[i]) {

return false;

}

}

return true;

}

/**

* 哈希

* @param s

* @param t

* @return

*/

private static boolean isAnagram2(String s, String t) {

HashMap<Character, Integer> map = new HashMap<>();

for (char c : s.toCharArray()) {

map.put(c, map.getOrDefault(c, 0) + 1);

}

for (char c : t.toCharArray()) {

Integer count = map.get(c);

if (count == null){

return false;

} else if (count > 1) {

map.put(c, count - 1);

} else {

map.remove(c);

}

}

return map.isEmpty();

}

}