var lengthOfLongestSubstring = function(s) {
let op = [];
let longestSubStr = 0;
s.split('').map((el,i) => {
let matchIndex = op.indexOf(el);
if(matchIndex == -1){
op.push(el);
}else{
//console.log("BEFORE-->",op)
longestSubStr = op.length > longestSubStr? op.length : longestSubStr;
op.splice(0,matchIndex+1);
op.push(el);
//console.log("AFTER-->",op,longestSubStr)
}
});
return op.length > longestSubStr? op.length : longestSubStr;
};
console.log(lengthOfLongestSubstring("abcabcbb"));
//"pwwkew" - 3
//"aab" -2
//"abcabcbb" -3
