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SPOJ Problem Set (classical)
50. Invitation Cards
Problem code: INCARDS
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In the age of television, not many people attend theater
performances. Antique Comedians of Malidinesia are aware of this fact. They
want to propagate theater and, most of all, Antique Comedies. They have
printed invitation cards with all the necessary information and with the
programme. A lot of students were hired to distribute these invitations
among the people. Each student volunteer has assigned exactly one bus stop
and he or she stays there the whole day and gives invitation to people
travelling by bus. A special course was taken where students learned
how to influence people and what is the difference between influencing
and robbery.
The transport system is very special: all lines are
unidirectional and connect exactly two stops. Buses leave
the originating stop with passangers each half an hour. After reaching
the destination stop they return empty to the originating stop,
where they wait until the next full half an hour, e.g. X:00 or
X:30, where 'X' denotes the hour. The fee for transport between two
stops is given by special tables and is payable on the spot. The
lines are planned in such a way, that each round trip (i.e. a journey
starting and finishing at the same stop) passes through a Central
Checkpoint Stop (CCS) where each passenger has to pass a thorough
check including body scan.
All the ACM student members leave the CCS each morning. Each volunteer is
to move to one predetermined stop to invite passengers. There are as many
volunteers as stops. At the end of the day, all students travel back to CCS.
You are to write a computer program that helps ACM to minimize the amount of
money to pay every day for the transport of their employees.
Input
The input consists of N cases. The first line of the input
contains only positive integer N. Then follow the cases.
Each case begins with a line containing exactly two integers
P and Q, 1 <= P,Q <= 1000000.
P is the number of stops including CCS and Q the
number of bus lines. Then there are Q lines, each describing one
bus line. Each of the lines contains exactly three numbers - the originating
stop, the destination stop and the price. The CCS is designated by
number 1. Prices are positive integers the sum of which is
smaller than 1000000000. You can also assume it is always
possible to get from any stop to any other stop.
Output
For each case, print one line containing the minimum amount of
money to be paid each day by ACM for the travel costs of its volunteers.
Example
Sample input:
2
2 2
1 2 13
2 1 33
4 6
1 2 10
2 1 60
1 3 20
3 4 10
2 4 5
4 1 50
Sample output:
46
210
Warning: large Input/Output data, be careful with certain languages
| Added by: | Adrian Kosowski |
| Date: | 2004-06-06 |
| Time limit: | 5s
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| Source limit: | 50000B |
| Languages: | All except: TECS |
| Resource: | ACM Central European Programming Contest, Prague 1998 |
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