Leetcode 2920. Maximum Points After Collecting Coins From All Nodes

• [Leetcode 2920. Maximum Points After Collecting Coins From All Nodes](#Leetcode 2920. Maximum Points After Collecting Coins From All Nodes)
  • [1. 解题思路](#1. 解题思路)
  • [2. 代码实现](#2. 代码实现)

• 题目链接：2920. Maximum Points After Collecting Coins From All Nodes

1. 解题思路

这一题思路上也很直接，就是一个深度优先遍历加上一个动态规划，分别考虑在两种情况下对应的coin收集数目，然后取最大值即可。

2. 代码实现

给出python代码实现如下：

class Solution:
    def maximumPoints(self, edges: List[List[int]], coins: List[int], k: int) -> int:
        graph = defaultdict(list)
        for u, v in edges:
            graph[u].append(v)
            graph[v].append(u)
            
        @lru_cache(None)
        def dp(u, p, m):
            if m >= 14:
                return 0
            val = coins[u] 
            for _ in range(m):
                val = val // 2
            ans = val - k
            for v in graph[u]:
                if v == p:
                    continue
                ans += dp(v, u, m)
            if val - k < val // 2:
                ans2 = val // 2
                for v in graph[u]:
                    if v == p:
                        continue
                    ans2 += dp(v, u, m+1)
                ans = max(ans, ans2)
            return ans
        
        ans = dp(0, -1, 0)
        return ans

提交代码评测得到：耗时3186ms，占用内存424.7MB。