[Swift]LeetCode339. 嵌套链表权重和 $ Nested List Weight Sum

Given a nested list of integers, return the sum of all integers in the list weighted by their depth.

Each element is either an integer, or a list -- whose elements may also be integers or other lists.

Example 1:
Given the list [[1,1],2,[1,1]], return 10. (four 1‘s at depth 2, one 2 at depth 1)

Example 2:
Given the list [1,[4,[6]]], return 27. (one 1 at depth 1, one 4 at depth 2, and one 6 at depth 3; 1 + 4*2 + 6*3 = 27)

每个元素要么是一个整数，要么是一个列表——其元素也可以是整数或其他列表。

例1：

给定列表[[1,1],2,[1,1]]，返回10。（深度2处4个1，深度1处1个2）

例2：

给定列表[1,[4,[6]]]，返回27。（深度1处1个1，深度2处1个4，深度3处1个6；1+4*2+6*3=27）

 1 class Solution {
 2     func depthSum(_ nestedList:inout [NestedInteger]) -> Int {
 3         retrurn helper(&nestedList, 1)
 4     }
 5
 6     func helper(_ nl:inout [NestedInteger],_ depth:Int) -> Int
 7     {
 8         var res:Int = 0
 9         for a in nl
10         {
11             if let num:Int = Int(a)
12             {
13                  res += (num * depth)
14             }
15             else
16             {
17                 var list = a.getList()
18                 res +=  helper(&list, depth + 1)
19             }
20         }
21         return res
22     }
23 }

原文地址：https://www.cnblogs.com/strengthen/p/10714683.html