leetcode3. Longest Substring Without Repeating Characters

Posted 2020-10-01 LOVEwitch

Given a string, find the length of the longest substring without repeating characters.

Examples:

Given "abcabcbb", the answer is "abc", which the length is 3.

Given "bbbbb", the answer is "b", with the length of 1.

Given "pwwkew", the answer is "wke", with the length of 3. Note that the answer must be a substring, "pwke" is a subsequenceand not a substring.

 

var lengthOfLongestSubstring = function(s) {
    if (s.length == 0) {return 0;}
    var longest = 0, p1 = 0, p2 = 0, hashmap = {};
    while(p2 < s.length) {
        if (hashmap[s[p2]] != undefined) {
            p1 = Math.max(hashmap[s[p2]]+1,p1)
        }
        longest = Math.max(longest,p2-p1+1);
        hashmap[s[p2]] = p2;
        p2++;
    }
    return longest;
};