158 · Valid Anagram - LintCode

# Description

Write a method anagram(s,t) to decide if two strings are anagrams or not.

What is Anagram?

Two strings are anagram if they can be the same after change the order of characters.

# Example

Example 1:

Input: s = "ab", t = "ab"
Output: true

Example 2:

Input:  s = "abcd", t = "dcba"
Output: true

Example 3:

Input:  s = "ac", t = "ab"
Output: false

Challenge

O(n) time, O(1) extra space

	public class Solution {
	/**
	* @param s: The first string
	* @param t: The second string
	* @return: true or false
	*/
	public boolean anagram(String s, String t) {
	int[] countS = new int[256];
	int[] countT = new int[256];

	for(int i = 0; i < s.length(); i++){
	countS[s.charAt(i)]++;
	}
	for(int i = 0; i < t.length(); i++){
	countT[t.charAt(i)]++;
	}
	for (int i = 0; i < 256; i++){
	if (countS[i] != countT[i]){
	return false;
	}
	}
	return true;
	}
	}

	public class Solution {
	/**
	* @param s: The first string
	* @param t: The second string
	* @return: true or false
	*/
	public boolean anagram(String s, String t) {
	Map<Character, Integer> hm = new HashMap<>();
	for (char c : s.toCharArray()) {
	hm.put(c, hm.getOrDefault(c, 0) + 1);
	}
	for (char c : t.toCharArray()) {
	if (hm.containsKey(c)) {
	hm.put(c, hm.get(c) - 1);
	if (hm.get(c) == 0) {
	hm.remove(c);
	}
	} else {
	return false;
	}
	}
	return hm.isEmpty();
	}
	}```