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
arvindkejriwal:
20170116 18:48:48
use cin instead of scanf 

prasoonbatham:
20170107 15:36:53
Top down recursion accepted easy problem :) 

datbeohbbh:
20161022 15:59:12
ez problem 

lalywr:
20161012 12:50:20
Negative Numbers in test cases :/ 

hamjosh1:
20160913 23:39:13
Silly mistake cost me 1 wa :'( 

madhavgaba:
20160908 18:22:52
Slight change to miserman problem :) 

santamaria:
20160907 14:52:55
That dot "." gives me *_* ... :( 

mohamedshehata:
20160902 14:52:22
Accepted recursive solution :D B in one go .. 

darkod3r:
20160726 19:45:14
Easy one !! if u r getting WA, first check silly mistakes :D .. like i was printing just answer insted of testcase_no. and then answer. :P , costed me 2 WA :P 

anuj0503:
20160624 07:59:17
Top Down Runtime Error !!!

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 