ACPC10D  Tri graphs
Here’s a simple graph problem: Find the shortest path from the topmiddle vertex to the bottommiddle vertex in a given trigraph. A trigraph is an acyclic graph of (N ≥ 2) rows and exactly 3 columns. Unlike regular graphs, the costs in a trigraph are associated with the vertices rather than the edges.
So, considering the example with N = 4, the cost of going straight down from the top to bottom along the middle vertices is 7 + 13 + 3 + 6 = 29. The layout of the directional edges in the graph are always the same as illustrated in the figure.
Input
Your program will be tested on one or more test cases.
Each test case is specified using N + 1 lines where the first line specifies a single integer (2 ≤ N ≤ 100, 000) denoting the number of rows in the graph. N lines follow, each specifying three integers representing the cost of the vertices on the ith row from left to right. The square of each cost value is less than 1,000,000.
The last case is followed by a line with a single zero.
Output
For each test case, print the following line:
k. n
Where k is the test case number (starting at one,) and n is the least cost to go from the topmiddle vertex to the bottommiddle vertex.
Example
Input:
4
13 7 5
7 13 6
14 3 12
15 6 16
0
Output:
1. 22
hide comments
ANSHUL ARZARE:
20141213 12:01:55
Easy but Nice problem :) 

« sudipto »:
20141111 19:31:12
AC after lots and lots of WA.... negative numbers should have been mentioned..... :/ .... still a lovely problem.... :) 

Manoj Kumar Regar:
20141024 12:53:37
Getting Wrong ans!..... so sad!


Arun Karthikeyan:
20141010 21:56:03
Simple DP 

codedog:
20140824 00:33:50
someone please help me,my program runs fine on my ide and passes all test cases. 

codedog:
20140824 00:33:08
no matter how hard i try, can't get rid of the runtime error 

codedog:
20140824 00:32:12
http://ideone.com/0TMFH7


Shaktiman:
20140823 16:16:39
Just do MISERMAN before it and then try this. So simple 

Darren Sun:
20140806 03:42:36
Additional testcases in the comments are useful. 

Varun Gambhir:
20140730 11:59:49
Awesome question.Learnt something new! 
Added by:  Omar ElAzazy 
Date:  20101130 
Time limit:  0.262s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 
Resource:  ACPC 2010 