SHPATH  The Shortest Path
You are given a list of cities. Each direct connection between two cities has its transportation cost (an integer bigger than 0). The goal is to find the paths of minimum cost between pairs of cities. Assume that the cost of each path (which is the sum of costs of all direct connections belongning to this path) is at most 200000. The name of a city is a string containing characters a,...,z and is at most 10 characters long.
Input
s [the number of tests <= 10] n [the number of cities <= 10000] NAME [city name] p [the number of neighbours of city NAME] nr cost [nr  index of a city connected to NAME (the index of the first city is 1)] [cost  the transportation cost] r [the number of paths to find <= 100] NAME1 NAME2 [NAME1  source, NAME2  destination] [empty line separating the tests]
Output
cost [the minimum transportation cost from city NAME1 to city NAME2 (one per line)]
Example
Input: 1 4 gdansk 2 2 1 3 3 bydgoszcz 3 1 1 3 1 4 4 torun 3 1 3 2 1 4 1 warszawa 2 2 4 3 1 2 gdansk warszawa bydgoszcz warszawa Output: 3 2
Warning: large Input/Output data, be careful with certain languages
hide comments
kygas:
20180401 23:08:47
No, no, I am supposed to teach kids the Dijkstra, and I am using this problem as an example.


nadstratosfer:
20180401 04:03:58
A state competition in ripping off someone else's code? By what criteria a winner is determined there, kygas? 

kygas:
20180331 20:59:25
I need a solution to this problem, would someone mind posting a link to it for a short time since I need it for the Monday for the preparation for the state competition, thanks in advance. :) 

anirudnits:
20180131 19:36:10
@kmkhan_014 thanks :) 

Shivam Gupta:
20171220 22:03:26
For those using dijkstra, another optimization that nobody seems to have mentioned is that instead of running dijkstra for each sourcedest pair, store all the queries and run dijkstra only once from each source vertex till all the dest. are found 

tzolkat:
20171114 03:00:45
I need a bigger file to test with. 

jha_gaurav98:
20171111 04:18:20
Don't perform the complete dijkstra...as soon as you remove the destination vertex from the heap just stop 

Adrian Motulewicz:
20171101 01:54:58
When I know that key node is satisfied? When can I break out of the Dijkstra? I wrote my code in java and I have problem with time :( Last edit: 20171101 01:56:53 

bani_raheja:
20171028 22:07:59
ac in one go!


kmkhan_014:
20171025 19:41:35
The edges are all directed. if assumed undirected the judge may throw TLE

Added by:  Darek Dereniowski 
Date:  20040510 
Time limit:  1.5s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  DASM Programming League 2003 (problemset 11) 