Nested List Weight Sum II

Problem: Nested List Weight Sum II

We can store the level when we scan through the nested list, or we can store the number in different slots in a list corresponding to their levels. The real depth can be easily computed with the biggest level known.

Code in Python:

# """
# This is the interface that allows for creating nested lists.
# You should not implement it, or speculate about its implementation
# """
#class NestedInteger(object):
#    def __init__(self, value=None):
#        """
#        If value is not specified, initializes an empty list.
#        Otherwise initializes a single integer equal to value.
#        """
#
#    def isInteger(self):
#        """
#        @return True if this NestedInteger holds a single integer, rather than a nested list.
#        :rtype bool
#        """
#
#    def add(self, elem):
#        """
#        Set this NestedInteger to hold a nested list and adds a nested integer elem to it.
#        :rtype void
#        """
#
#    def setInteger(self, value):
#        """
#        Set this NestedInteger to hold a single integer equal to value.
#        :rtype void
#        """
#
#    def getInteger(self):
#        """
#        @return the single integer that this NestedInteger holds, if it holds a single integer
#        Return None if this NestedInteger holds a nested list
#        :rtype int
#        """
#
#    def getList(self):
#        """
#        @return the nested list that this NestedInteger holds, if it holds a nested list
#        Return None if this NestedInteger holds a single integer
#        :rtype List[NestedInteger]
#        """

class Solution(object):
    def depthSumInverse(self, nestedList):
        """
        :type nestedList: List[NestedInteger]
        :rtype: int
        """
        vals = []

        def get_value(nestedList, depth):
            if len(vals) < depth:
                vals.append([])
            for item in nestedList:
                if item.isInteger():
                    vals[depth - 1].append(item.getInteger())
                else:
                    get_value(item.getList(), depth + 1)
        get_value(nestedList, 1)
        return sum((len(vals) - idx) * sum(vals_item) for idx, vals_item in enumerate(vals))