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
abdou_93:
20130113 07:56:48
@janani the answer of


Janani:
20130106 03:45:10
@tantu28 : how 32, i am getting 23!


MR. BEAN :
20121217 12:22:12
forgot to change the line, costed 2 WA ! 

tantu92:
20121015 14:18:44
@janani:its 32 

Janani:
20121015 01:03:49
What should be the answer for


Rahul kumar:
20121012 09:24:15
more test cases pls... 

Aaquib Ishtiyaq:
20120922 21:31:03
AC in second try..... HUH!! was not printing correct format... 

gabber:
20120918 20:52:58
negative numbers huh...


saket diwakar:
20120703 10:45:01
enjoyed to solve it....got AC in first try.:) 

amit:
20120525 09:41:16
Last edit: 20120525 10:07:56 
Added by:  Omar ElAzazy 
Date:  20101130 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 
Resource:  ACPC 2010 