GFG 175 Longest Increasing Path in Tree

You are given a tree of n nodes and n-1 undirected edges . You are also given an array values ,

where values[i] represent the value on i node . You have to  nd the length of the longest strictly

increasing path in the tree.(1-based indexing is used)

Example 1:

Input:

n = 3

edges = {{1,2}, {1,3}}

values = {4, 3, 5}

Output:

3

Explanation:

as we can see in the tree , the longest strictly increasing path is 2 -> 1 -> 3 as 

their values(3, 4, 5) are in strictly increasing order;

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我直接dfs做，结果超时了，因为是对每个点都进行dfs，然后也没有保存结果，所以就超时了，参考别的ac的代码，就是新建一个数组，dp，保存每个点数据，然后取最大值即可。

python的话，直接加个cache就行。

学到了这个dp，以后得试试。