3. Longest Substring Without Repeating Characters

/**
 * @param {string} s
 * @return {number}
 */

var lengthOfLongestSubstring = function (s) {
	const len = s.length
	let substringHash = {},
		count = 0,
		maxCount = 0,
		i = 0,
		j = 0
	while (i < len) {
		const char = s[i]
		if (substringHash[char] === undefined) {
			substringHash[char] = i
			count++
		} else {
			maxCount = Math.max(count, maxCount)
			let k = substringHash[char] + 1
			j = k
			count = 0
			substringHash = {}
			while (k <= i) {
				substringHash[s[k]] = k
				count++
				k++
			}
		}
		i++
	}
	return Math.max(count, maxCount)
}

//Test cases
console.log(lengthOfLongestSubstring('abcabcbb'))
console.log(lengthOfLongestSubstring('bbbbb'))
console.log(lengthOfLongestSubstring('pwwkew'))
console.log(lengthOfLongestSubstring('dvdf'))
console.log(lengthOfLongestSubstring('abba'))
console.log(lengthOfLongestSubstring('jbpnbwwd'))