763. Partition Labels

• store the last index for each occurrence to an dictionary

class Solution(object):
    def partitionLabels(self, s):
        lastIndex = {}

        for i, c in enumerate(s):
            lastIndex[c] = i


        res = []
        size, end = 0, 0

        for i, c in enumerate(s):
            size += 1
            end = max(end, lastIndex[c])

            if i == end:
                res.append(size)
                size = 0

        return res