var lengthOfLongestSubstring = function(s) {
s = s.split('')
if(s<= 1) return s.length
let maxArr = [],maxLen = []
while(s.length) {
const currentNode = s.shift()
const index = maxArr.indexOf(currentNode)
if(index === -1) {
maxArr.push(currentNode)
} else {
maxLen.push(maxArr.length)
maxArr = maxArr.slice(index+1)
// console.log(maxArr)
maxArr.push(currentNode)
}
}
maxLen.push(maxArr.length)
return Math.max(...maxLen)
};