Leet Code 3. Longest Substring Without Repeating Characters

https://leetcode.com/problems/longest-substring-without-repeating-characters/

Example 1:

Input: s = "pwwkew"
Output: 3
Explanation: The answer is "wke", with the length of 3.
Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.

package pep.Day63;

import java.util.HashMap;

public class LeetCode_3_Longest_Substring_Without_Repeating_Characters {
    public static void main(String[] args) {
        System.out.println(lengthOfLongestSubstring("tmmzuxt"));
    }

    public static int lengthOfLongestSubstring(String s) {
        char[] arr = s.toCharArray();
        HashMap<Character, Integer> map = new HashMap<>();
        int length = 0;
        int left = 0;
        for (int right = 0; right < arr.length; right++) {
            char ch = arr[right];
            if (map.containsKey(ch))
                left = Math.max(left, map.get(ch) + 1);
            map.put(ch, right);
            length = Math.max(length, right - left + 1);

        }

        return length;
    }

    public static int lengthOfLongestSubstring1(String s) {
        HashMap<Character, Integer> map = new HashMap<>();
        int length = 0;
        int left = 0, right = 0;

        while (right < s.length()) {

            if (map.containsKey(s.charAt(right)))
                left = Math.max(left, map.get(s.charAt(right)) + 1);
            map.put(s.charAt(right), right);
            length = Math.max(length, right - left + 1);
            right++;
        }
        return length;
    }

}