Balancing Bank Accounts
Time Limit: 1 Second Memory Limit: 32768 KB
Special Judge
In the previous weeks, there had been many money transactions between them: Sometimes somebody paid the entrance fees of a theme park for the others, somebody else paid the hotel room, another one the rental car, and so on.
So now the big calculation started. Some people had paid more than others, thus the individual bank accounts had to be balanced again. "Who has to pay whom how much?", that was the question.
As such a calculation is a lot of work, we need a program now that will solve this problem next year.
Input
The input will contain one or more test cases.
Each test case starts with a line containing two integers: the number of travellers
n (2 <= n <= 20) and the number of transactions t (1 <= t <= 1000).
On the next n lines the names of the travellers are given, one per line. The
names only consist of alphabetic characters and contain no whitespace. On the
following t lines, the transactions are given in the format name1 name2 amount
where name1 is the person who gave amount dollars to name2. The amount will
always be a non-negative integer less than 10000.
Input will be terminated by two values of 0 for n and t.
Output
For each test case, first print a line saying "Case #i" where i is
the number of the test case.
Then, on the following lines, print a list of transactions that reverses the
transactions given in the input, i.e. balances the accounts again. Use the same
format as in the input. Print a blank line after each test case, even after
the last one.
Additional restrictions:
- Your solution must consist of at most n-1 transactions.
- Amounts may not be negative, i.e. never output "A B -20", output "B A 20" instead.
If there is more than one solution satisfying these restrictions, anyone is fine.
Sample Input
2 1 Donald Dagobert Donald Dagobert 15 4 4 John Mary Cindy Arnold John Mary 100 John Cindy 200 Cindy Mary 40 Cindy Arnold 150 0 0
Sample Output
Case #1 Dagobert Donald 15 Case #2 Mary John 140 Cindy John 10 Arnold John 150Submit
Source: University of Ulm Local Contest 1998