339. Nested List Weight Sum

最新推荐文章于 2022-05-28 10:01:37 发布

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最新推荐文章于 2022-05-28 10:01:37 发布

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原文链接：http://www.cnblogs.com/renyualbert/p/5902320.html

本文介绍了一种针对嵌套整数列表的深度加权求和算法。该算法通过递归遍历列表，根据元素的深度计算其权重，并返回所有元素的加权总和。例如，对于列表[[1,1],2,[1,1]]，四个1位于深度2，一个2位于深度1，因此结果为10。

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)

DFS

public int DepthSum(IList<NestedInteger> nestedList) {
        return Depth(nestedList,1);
    }
    
    public int Depth(IList<NestedInteger> nestedList, int depth)
    {
        int res =0;
        if(nestedList.Count()==0)
        {
            return res;
        }
        else
        {
            foreach(var n in nestedList)
            {
                if(n.IsInteger()) res += n.GetInteger()* depth;
                else    res += Depth(n.GetList(),depth+1);
            }
            return res;
        }
    }