TRT - Treats for the Cows

FJ has purchased N (1 <= N <= 2000) yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period time. The treats are interesting for many reasons:

  • The treats are numbered 1..N and stored sequentially in single file in a long box that is open at both ends. On any day, FJ can retrieve one treat from either end of his stash of treats.
  • Like fine wines and delicious cheeses, the treats improve with age and command greater prices.
  • The treats are not uniform: some are better and have higher intrinsic value. Treat i has value v(i) (1 <= v(i) <= 1000).
  • Cows pay more for treats that have aged longer: a cow will pay v(i)*a for a treat of age a.

Given the values v(i) of each of the treats lined up in order of the index i in their box, what is the greatest value FJ can receive for them if he orders their sale optimally?

The first treat is sold on day 1 and has age a=1. Each subsequent day increases the age by 1.

Input

Line 1: A single integer, N

Lines 2..N+1: Line i+1 contains the value of treat v(i)

Output

The maximum revenue FJ can achieve by selling the treats

Example

Input:
5
1
3
1
5
2

Output:
43

Added by:Nguyen Van Quang Huy
Date:2006-02-15
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: NODEJS PERL6 VB.NET
Resource:USACO FEB06 Gold Division

hide comments
2013-05-27 19:52:56 shiva_hellgeek
An excellent problem on DP for begginers like me. :)
2013-05-26 11:18:39 shashank
plz everyone join irc at #spoj
2013-05-22 05:36:08 Sampath Kumar
give some tricky test cases.. getting WA , though i have tried many cases for which my algo is giving correct ans..

GOT AC..

Last edit: 2013-05-22 05:56:22
2013-05-16 04:48:16 $!:D


Last edit: 2013-05-21 08:11:13
2013-04-26 08:25:44 Ouditchya Sinha
Good DP problem, top down worked for me :)
2013-04-08 18:34:19 mohit rathi
Simple DP..:D
2013-03-07 15:20:47 Hani
somone provide more test cases.........???????
2013-02-01 18:28:11 Akshaya Gupta
nice dp
2013-01-14 11:24:31 innovolt
smone provide more test cases.........???????
2012-12-24 20:17:27 gourav
nice problem.. but just do it if u r beginner.. still gave 3-4 WA :'(
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