LeetCode 339. Nested List Weight Sum

最新推荐文章于 2020-05-10 12:23:22 发布

原创最新推荐文章于 2020-05-10 12:23:22 发布 · 499 阅读

0 ·

CC 4.0 BY-SA版权

LeetCode 题解专栏收录该内容

288 篇文章

订阅专栏

本文介绍了一种通过递归方法解决带权重的嵌套整数列表求和问题，详细解释了算法实现，并通过两个例子展示了如何计算不同深度整数的加权和。

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)

This question is a simplified version of DFS

class Solution {
public:
    int DFS(vector<NestedInteger>& nestedList, int depth)
    {
        int sum = 0;
        for(auto val: nestedList)
        {
            if(val.isInteger())
                sum += val.getInteger()*depth;
            else sum += DFS(val.getList(), depth+1);
        }
        return sum;
    }
    
    int depthSum(vector<NestedInteger>& nestedList) {
        return DFS(nestedList, 1);
    }
};