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
shikhar_may7:
20200217 20:03:49
CAUTION: ve nodes ahead! Last edit: 20200217 20:04:06 

ak8325:
20200101 23:16:21
If you are getting WA.. ask yourself


akash619j:
20190817 21:11:37
Can cost be negative? I think its not clearly mentioned in the problem statement... 

anand_undavia:
20190623 09:31:56
Java: br.readLine().split("\\s+"); Gave me TLE :P


cenation007:
20190620 09:00:37
easy peasy lemon squeezy


aryan29:
20190608 15:22:43
DP is amazing my 2nd DP problem AC in 1 go but overcomplicate it 

sahilsinghss:
20190326 10:49:33
Wohoo 100 done 

bloodgreed99:
20190127 15:03:15
DP introductory question 

gaurav1614:
20181226 21:34:06
very easy problem.think in terms of reachable and unreachable nodes. 

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