Problem B
Choir of Birds
In a large tree there is a choir of $N$ birds, one at each node. At any given node of the tree, the chirp from the bird at node $i$ can be heard with a sound volume of $floor(A_ i / (B_ i + d^2))$, where $A_ i$ and $B_ i$ are constants and $d$ is the distance to the bird when walking along the branches. At which node of the tree is the total volume the loudest?
Input
The first line contains a single number $N$ ($1 \le N \le 25000$), the number of nodes in the tree. The $N$ following lines contain two numbers each, $A_ i$ ($0 \le A_ i \le 25$) and $B_ i$ ($1 \le B_ i \le 25$), the constants for node $i$ ($0 \le i \le N-1$). The $N-1$ lines following that contain two numbers each, $p_ j$ and $q_ j$, the nodes connected by edge number $j$. The graph does not contain a cycle.
Output
A single number, the index of the node where the total volume is the loudest.
Test cases
There are three groups of test cases. To get the points for a group you need to succeed on all test cases in the group.
Group |
Points |
Limits |
$1$ |
$25$ |
$N \le 1000$ |
$2$ |
$30$ |
$A_ i > 0$ in at most $10$ nodes; $A_ i=0$ in all other nodes |
$3$ |
$45$ |
No further restrictions |
Sample Input 1 | Sample Output 1 |
---|---|
5 27 3 40 2 32 24 46 30 21 25 4 3 1 4 2 3 0 3 |
1 |
Sample Input 2 | Sample Output 2 |
---|---|
8 19 29 34 21 43 17 0 4 30 36 4 1 46 6 12 5 3 1 2 7 7 5 4 1 0 6 5 0 1 6 |
5 |