3.无重复字符的最长子串.js

/*
 * @lc app=leetcode.cn id=3 lang=javascript
 *
 * [3] 无重复字符的最长子串
 */

// @lc code=start
/**
 * @param {string} s
 * @return {number}
 */
var lengthOfLongestSubstring = function(s) {
    const map = {};
    var left = 0;
    return s.split('').reduce((max, v, i) => {
        left = map[v] >= left ? map[v] + 1 : left;
        map[v] = i;
        return Math.max(max, i - left + 1);
    }, 0);
};
// @lc code=end



// @after-stub-for-debug-begin
module.exports = lengthOfLongestSubstring;
// @after-stub-for-debug-end