题目
You are given a nested list of integers nestedList. Each element is either an integer or a list whose elements may also be integers or other lists.
The depth of an integer is the number of lists that it is inside of. For example, the nested list [1,[2,2],[[3],2],1] has each integer’s value set to its depth.
Return the sum of each integer in nestedList multiplied by its depth.
解题思路
递归，遍历list里的每个item，如果是数，直接用depth计算结果，如果是list，depth+1，遍历这个list
代码
# """
# This is the interface that allows for creating nested lists.
# You should not implement it, or speculate about its implementation
# """
#class NestedInteger:
# 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:
def depthSum(self, nestedList: List[NestedInteger]) -> int:
def find(nested, depth):
ret = 0
for item in nested:
print(item)
if item.isInteger():
ret += item.getInteger() * depth
else:
ret += find(item.getList(), depth + 1)
return ret
return find(nestedList, 1)
