classSolution {

funlengthOfLongestSubstring(s:String):Int {

val hs=HashSet<Char>()

var i=0

var j=0

var maxLength=0

while (j< s.length) {

if (hs.contains(s[j])) {

hs.remove(s[i++])

}else {

hs.add(s[j++])

maxLength= maxLength.coerceAtLeast(hs.size)

}

}

return maxLength

}

}