A Heavy Light Decomposition Problem

Revision en2, by flash_7, 2015-09-23 00:34:29

I was trying to solve this problem but getting WA.I used heavy light decomposition technique to solve it.But can't find out any case where my code fails.

Here is my code link.

I would relly appreciate if anyone help me finding my error.

Problem Description:

Finally the Great Magical Lamp was in Aladdins hand. Now he wanted to return home. But he didnt want to take any help from the Genie because he thought that it might be another adventure for him. All he remembered was the paths he had taken to reach there. But since he took the lamp, all the genies in the cave became angry and they were planning to attack. As Aladdin was not afraid, he wondered how many genies were there. He summoned the Genie from the lamp and asked this.

Now you are given a similar problem. For simplicity assume that, you are given a tree (a connected graph with no cycles) with n nodes, nodes represent places, edges represent roads. In each node, initially there are an arbitrary number of genies. But the numbers of genies change in time. So, you are given a tree, the number of genies in each node and several queries of two types. They are:

1)      0 i j, it means that you have to find the total number of genies in the nodes that occur in path from node i to j (0 ≤ i, j < n).
2)      1 i v, it means that number of genies in node i is changed to v (0 ≤ i < n, 0 ≤ v ≤ 1000).

Input
Input starts with an integer T (≤ 10), denoting the number of test cases.

Each case starts with a blank line. Next line contains an integer n (2 ≤ n ≤ 30000). The next line contains n space separated integers between 0 and 1000, denoting the number of genies in the nodes respectively. Then there are n-1 lines each containing two integers: u v (0 ≤ u, v < n, u ≠ v) meaning that there is an edge from node u and v. Assume that the edges form a valid tree. Next line contains an integer q (1 ≤ q ≤ 105) followed by q lines each containing a query as described above.

Output
For each case, print the case number in a single line. Then for each query 0 i j, print the total number of genies in the nodes that occur in path i to j.


Sample Input:
1
 
4
10 20 30 40
0 1
1 2
1 3
3
0 2 3
1 1 100
0 2 3

Sample Output:
Case 1:
90
170

Tags data structures, hld, segment tree, lca

History

 
 
 
 
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  Rev. Lang. By When Δ Comment
en2 English flash_7 2015-09-23 00:34:29 32
en1 English flash_7 2015-09-23 00:32:45 2423 Initial revision (published)