• https://leetcode.com/problems/longest-substring-without-repeating-characters/
• 3. Longest Substring Without Repeating Characters

JavaScript 解答

var lengthOfLongestSubstring = function (s) {

    var max = 0;
    var i = 0;
    var j = 0;
    var n = s.length;
    var map = {};

    while (i < n && j < n) {
        if (map[s[j]] === undefined) {
            map[s[j]] = 1;
            j++;
            max = Math.max(max, j - i);
        } else {
            delete map[s[i]];
            i++;
        }

    }

    return max;
};

Ruby 解答

def length_of_longest_substring(s)    
    max = 0

    for i in 0..s.length-1
        check = Array.new(256, false)
        for j in i..s.length-1
            index = s[j].ord
            if check[index] == false
                check[index] = true
            else
                break
            end
            
        end
        if check.count(true) > max      
            max = check.count(true)
        end
    end
    max
end