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PRLOVE - Expected Time to Love

Alice has a problem. She loves Bob but is unable to face up to him. So she decides to send a letter to Bob expressing her feelings. She wants to send it from her computer to Bob's computer through the internet.

The internet consists of N computers, numbered from 1 to N. Alice's computer has the number 1 and Bob's computer has the number N.

Due to some faulty coding, the computers start behaving in unexpected ways. On recieving the file, computer i will forward it to computer j with probability Pij. The time taken to transfer the file from computer i to computer j is Tij.

Find the expected time before Bob finds out about Alice's undying love for him.

Note: Once the letter is recieved by Bob's computer, his computer will just deliver it to Bob and stop forwarding it.

Input

First line contains T, the total test cases.

Each test case looks as follows:

First line contains N, the total number of computers in the network.

The next N lines contain N numbers each. The j'th number on the i'th line is the value Pij in percents.

The next N lines contain N numbers each. The j'th number on the i'th line is the value Tij.

Output

Output a single line with a real number - The expected time of the transfer.

Your output will be considered correct if each number has an absolute or relative error less than 106.

Constraints

N100

T5

For all i, Pi1+Pi2++PiN=100

PNN=100

For all i, j, 0Tij10000

You can safely assume that from every computer, the probability of eventually reaching Bob's computer is greater than 0.

Example

Sample Input:
2
4
0 50 50 0
0 0 0 100
0 0 0 100
0 0 0 100
0 2 10 0
0 0 0 0
0 0 0 0
0 0 0 0
2
99 1
0 100
10 2
0 0

Sample Output:
6.000000
992.000000

Added by:Aditya
Date:2013-02-03
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:BASH C C++ 4.3.2 CPP FORTRAN HASK JAVA PAS-GPC PAS-FPC PYTHON PYTHON3 PY_NBC RUBY SCALA WHITESPACE
Resource:ByteCode '13

hide comments
2018-05-23 09:10:29 akshay
@thomas underflow... log sum exp trick is your friend ...
2017-12-16 23:55:08 Thomas Dybdahl Ahle
Say you have a chain, where each computer has probability 1% of sending to the next computer, and 99% of sending to the first. Then the message would have to travel more than 100^100 times to get to Bob, in expectation. With the bounds on T, that means the answer can be as large as 10^204. Is that correct? Getting 10^-6 absolute precision on numbers that large is pretty difficult.

Last edit: 2017-12-16 23:55:44
2013-03-08 11:45:04 The Mundane Programmer
Can anyone explain test cases......
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