无重复字符的最长子串

function lengthOfLongestSubstring(s: string): number {
    let a:string[] = s.split(''), temp:string[] = [], max:number = 0;
    a.forEach(i => {
        if (temp.includes(i)) {
            temp.splice(0, temp.indexOf(i)+1)
            temp.push(i)
        } else {
            temp.push(i)
            max = max > temp.length ? max : temp.length
        }
    })
    return max
};