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
masterchef2209:
20181011 23:29:50
simple dp with a small corner case 

be1035016:
20180619 12:39:46
define your own maxima if you are using it.dont rely on LONG_MAX in c++. 

foool:
20180617 00:54:12
top down AC.... 

ducky94tb:
20180111 18:03:46
My careless, wasted too many time Last edit: 20180111 18:05:10 

bani_raheja:
20180102 20:14:10
easy af. Perfect example of "DP is nothing but brute force" 

sdeven_0245:
20171231 13:03:43
Easy one !!!! 

dushyant7917:
20171219 12:29:59
@karthik1997 why for testcase:


karthik1997:
20171215 09:30:33
Note :


jha_gaurav98:
20171018 08:59:36
The cost of vertices can even be negative. Costed me 1 wa 

gourav_123:
20171017 23:47:30
after this solve http://www.spoj.com/problems/BYTESM2/ 
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 