Submit | All submissions | Best solutions | Back to list |
AMR10H - Shopping Rush |
A shop-keeper is trying to figure out how to arrange gifts in his shop for Christmas. He runs a peculiar shop such that each customer buys exactly two gifts at the shop (he could buy two of the same gifts too). He knows the probability that a customer might want gift i, is Pi.
He needs to arrange the gifts across several floors. Each floor should have exactly one gift. It takes A*(|x - y|)2 + B*(|x - y|) + C seconds to go from floor x to floor y.
Can you help him arrange the gifts across floors such that, the expected time spent by a shopper is minimized?
For the purpose of this problem assume that the first gift choice and the second gift choice are independent of each other. i.e., Choosing a first gift as i does not change his probability of choosing the second gift as j. It still remains Pj.
Input
The first line contains the number of test cases T. 2*T lines follow, 2 per test case. The first line contains 4 integers : N, A, B, C. The second line contains N integers in the range 1 to 100. The ith integer represents the percentage probability Pi. All Pi's will sum to 100.
Output
Output T lines one for each test case. Each line contains the minimum expected travelling time for the corresponding test case. Output the answer as a reduced fraction as below.
Constraints
1 ≤ T ≤ 100
1 ≤ N ≤ 20
0 ≤ A, B, C ≤ 10
Example
Input: 4 3 0 1 0 60 10 30 1 1 1 0 100 1 1 1 3 100 4 3 7 2 25 25 25 25 Output: 3/5 0/1 3/1 73/4
Added by: | Varun Jalan |
Date: | 2010-12-13 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
Resource: | own problem, ICPC Asia regionals, Amritapuri 2010 |