Product of Diameters
All submissions for this problem are available.
Read problems statements in Mandarin Chinese, Russian and Vietnamese as well.
Chef had a tree T with weighted nodes.
One day he decided that he wants to have two trees instead of one. So, he removed one of the edges of T.
The next day, he decided to have three trees instead of two. So, he removed one more edge from some of the trees he had.
And so on. Every day, Chef was removing one, not yet removed edge, util he once got a forest, consisting of N single-node trees.
Chef thinks that the main characteristic of a tree is its' diameter. So he asks you to calculate the product of the diameters in obtained set of trees.
Since the overall product might be quite large, output it modulo 109+7.
In this problem, we consider the diameter of the tree as the maximum sum of weights of the nodes over all simple paths in this tree.
The first line of the input contains an integer N denoting the number of nodes in the tree T.
The following line contains N space-separated integers Wi, denoting the weights of the nodes.
Each of the following (N-1) lines contain two space-separated integers Xi Yi.
Each of the following (N-1) lines contain a single integer Kj, denoting the number of the edge that will be deleted on the jth day.
Output N lines.
On the ith line, output the product of the diameters of all the trees after (i-1) days modulo 109+7. Formally, if i > 1, output the product of the diameters of the obtained trees after deleting the edges K1, K2, ..., Ki - 1, modulo 109+7, otherwise output the diameter of the initial tree.
- 1 ≤ N ≤ 105
- 1 ≤ Wi ≤ 104
- 1 ≤ Xi, Yi ≤ N
- K is a permutation of the integers from the range [1; N-1].
- Subtask #1 (16 points): 1 ≤ N ≤ 100
- Subtask #2 (24 points): 1 ≤ N ≤ 5000
- Subtask #3 (60 points): no additional constraints
Input: 3 1 2 3 1 2 1 3 2 1 Output: 6 9 6
The diameter of the initial tree is 6 (node 2 to node 1 to node 3).
After the first day (the deletion of the 2nd edge, i.e. 1 3), we get two trees, both with diameters 3.
After the second day (the deletion of the 1st edge, i.e. 1 2), we get three trees with diameters 1, 2, 3, and their product equals to 6.
|Tags||lca, ltime39, medium, tree, union-find, xcwgf666|
|Time Limit:||1 sec|
|Source Limit:||50000 Bytes|
|Languages:||C, CPP14, JAVA, PYTH, PYTH 3.6, PYPY, CS2, PAS fpc, PAS gpc, RUBY, PHP, GO, NODEJS, HASK, SCALA, D, PERL, FORT, WSPC, ADA, CAML, ICK, BF, ASM, CLPS, PRLG, ICON, SCM qobi, PIKE, ST, NICE, LUA, BASH, NEM, LISP sbcl, LISP clisp, SCM guile, JS, ERL, TCL, PERL6, TEXT, SCM chicken, CLOJ, FS|
Fetching successful submissions
If you are still having problems, see a sample solution here.