<script>
var str = 'aaaaaaaaaaaabababbbbbbbbbbbbcccccccccccccccccdddd'
var fir = 0,
maxLen = 0
for(var i = 1; i < str.length; i++) {
// console.log(str[i])
if(str[fir] != str[i]) {
console.log(i-fir)
fir = i
}
if((i+1) == str.length) {
console.log((i+1)-fir)
}
}
</script>
