lengthOfLongestSubstring

function lengthOfLongestSubstring(s) {
    let maxLength = 0;
    let indexMap = {};

    for (let i = 0, j = 0; j < s.length; j++) {
        if (indexMap[s[j]] !== undefined) {
            i = Math.max(indexMap[s[j]] + 1, i);
        }
        maxLength = Math.max(maxLength, j - i + 1);
        indexMap[s[j]] = j;
    }

    return maxLength;
}


console.log(lengthOfLongestSubstring("abcabcbb"));
console.log(lengthOfLongestSubstring("bbbb"));