CodeChef: Codechef
Site under maintenance
  • Register
  • Forgot Password?
  • PRACTICE
    • Easy
    • Medium
    • Hard
  • COMPETE
    • August Mini Challenge
    • August Algorithm Challenge
    • July Algorithm Challenge
    • June Algorithm Challenge
    • May Gamers Challenge
  • DISCUSS
    • Forums
    • Blog
    • Twitter
  • COMMUNITY
    • CodeChef TechTalks
    • CodeChef Meetups
    • Campus Chapters
    • Host Your Contest
    • User Groups
  • HELP
    • Frequently Asked Questions
    • FAQ for Problem Setters
    • Tutorial: Paying Up
    • Tutorial: Small Factorials
    • Tutorial: Input and Output(I/O)
    • Tutorial: Your First Non-Trivial Problem
  • ABOUT
    • About CodeChef
    • About Directi
    • CEO's Corner
    • Press Room
    • Careers

Home » Problems (medium) » Collect the Chocolate Chips

Collect the Chocolate Chips

Problem code: TKCHOCS

  • Submit
  • All submissions

All submissions for this problem are available.

Did you know that chocolate chip cookie was invented by accident ? They even declared May 15 as National Chocolate Chip day :). Po and Mantis love choco chips and they want to collect them on the board. The board is in the shape of a right-angled triangle having N rows, with i cells in the ith row ( 1-based indices, as shown below for N=4 ). Cell (i,j) refers to the cell in jth column in the ith row.

Po starts from the top-most cell (1,1) and from a cell (i,j) Po can move to any of the cells (i+1,j-1), (i+1,j) or (i+1,j+1) in one step, if it exists. Mantis starts from the right-most cell (N,N) and from a cell (i,j) Mantis can move to any of the cells (i-1,j-1), (i,j-1) or (i+1,j-1) in one step, if it exists. When Po or Mantis are in a cell, they can collect all the choco chips in it. They both want to reach the bottom-left cell (N,1) after collecting as many choco chips as possible. Find the maximum number of choco chips they can collect i.e., maximize the sum of chips collected by each of them.

1 2 3 4
1 Po
(1,1)
2 (2,1) (2,2)
3 (3,1) (3,2) (3,3)
4 (4,1)
Exit
(4,2) (4,3) (4,4)
Mantis

Input

First line contains an integer T (number of test cases, around 10 ). T cases follow. Each case starts with a line having an integer N ( 2 <= N <= 500 ). N lines follow with ith line having i non-negative integers from range [0 - 1,000,000], number of chips in each cell as explained above.

Output

For each case, output the maximum number of choco chips Po and Mantis can collect, in a separate line.

Example

Input:
2
2
1
1 1
3
1
2 5
1 3 1

Output:
3
11

Explanation:
Case 2 : Po can visit (1,1) -> (2,2) -> (3,1) and Mantis can visit (3,3) -> (3,2) -> (3,1). Note that if both step in to a same cell, we must count the choco chips in it only once in the final answer. The cell (3,1) is reached by both, but the 1 choco chip in it must be added only once ( of course :) ).


Date:2011-08-19
Time limit:3s
Source limit:50000B
Languages:All


  • Submit

Comments

Loading Comments...

SUCCESSFUL SUBMISSIONS FOR THIS PROBLEM:

Loading Submissions...

RECENT ACTIVITY FOR THIS PROBLEM:

Loading Recent Activity...

HELP

Program should read from standard input and write to standard output.

After you submit a solution you can see your results by clicking on the [My Submissions] tab on the problem page. Below are the possible results:

  • Accepted Your program ran successfully and gave a correct answer. If there is a score for the problem, this will be displayed in parenthesis next to the checkmark.
  • Time Limit Exceeded Your program was compiled successfully, but it didn't stop before time limit. Try optimizing your approach.
  • Wrong Answer Your program compiled and ran succesfully but the output did not match the expected output.
  • Runtime Error Your code compiled and ran but encountered an error. The most common reasons are using too much memory or dividing by zero. For the specific error codes see the help section.
  • Compilation Error Your code was unable to compile. When you see this icon, click on it for more information.

If you are still having problems, see a sample solution here.

  • About CodeChef
  • About Directi
  • CEO's Corner
  • Careers
  • feedback@codechef.com

© 2009 Directi Group. All Rights Reserved. CodeChef uses SPOJ © by Sphere Research Labs

Sponsors
The time now is: