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
2015-01-20 18:40:48 Jumpy
It took so long to solve this problem. First I did Greedy - Failed. Then Recursive - TLE. After that DP - GOT AC with 0.00 sec and 18MB memory.
2015-01-16 16:25:38 Sampath Ravolaparthi
OMG! I'm too Greedy!!!
Don't know what to do....??
Will try again later.....;)
2015-01-15 19:41:06 Asheesh Pathak
@Sampath Kumar Please tell me how you got AC. I'm having the same problem.
2015-01-11 16:49:54 Lokesh
Top Down approach caused tle
2015-01-01 16:32:32 KAI
easy DP, silly mistake costed wa's :)
2014-12-19 19:13:05 ALISHA
its worth only with bottom up.
atleast it's 0.03 s faster in c++!! :D
2014-12-18 13:47:03 eightnoteight
O(n) space and O(n*n) time complexity solution in python is giving tle,,
the time limit is too strict
2014-12-14 12:04:19 agaurav77
If you are getting RE (SIGSEGV), try replacing int arr[N][N] and items[N] with arr[2001][2001] and items[2001]. AC finally!
2014-12-06 19:21:48 Dhruv Mullick
Going Top Down destroys the fun. Try using Bottom up approach :)

Last edit: 2014-12-06 19:22:02
2014-12-03 15:23:27 Vaibhav Gosain
do TWENDS if u are having a problem with this one :)
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