3. Longest Substring Without Repeating Characters

[Tcdian]

3. Longest Substring Without Repeating Characters

给定一个字符串，请你找出其中不含有重复字符的 最长子串 的长度。

Example 1

Input: "abcabcbb"
Output: 3 
Explanation: The answer is "abc", with the length of 3. 

Example 2

Input: "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.

Example 3

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

[Tcdian]

Solution

• JavaScript Solution

/**
 * @param {string} s
 * @return {number}
 */
var lengthOfLongestSubstring = function(s) {
    const cache = new Set();
    let result = 0;
    for (let l = 0, r = 0; r < s.length; r++) {
        if (!cache.has(s[r])) {
            cache.add(s[r]);
        } else {
            while (s[l] !== s[r]) {
                cache.delete(s[l++]);
            }
            l++;
        }
        result = Math.max(result, r - l + 1);
    }
    return result;
};