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LCPC12F - Johnny The Gambler |
Johnny is a gambling addict. He entered a casino and started playing a game with the dealer. The game is as follows: the dealer deals a sequence of N cards, each card containing a number C[i] and asks Johnny how many pairs (j, k) such that j < k and C[j] + C[k] = X. If Johnny answers correctly he wins, otherwise the dealer wins.
Input
The first line of input contains an integer T, the number of test cases. T test cases follow, Each test case start with the value of 0 ≤ X ≤ 2*103 followed by the number of cards 0 < N ≤ 105 followed by N numbers representing the numbers on the cards 0 ≤ C[i] ≤ 103.
Output
There should be T lines, containing the following format.
k. S
Where k is the test case number (starting at 1), a single period, a single space and S representing the number of valid pairs (j, k) as described above.
Sample
Input 1 10 3 1 5 9 Output 1. 1
| Added by: | Gareev |
| Date: | 2012-10-06 |
| Time limit: | 1s |
| Source limit: | 50000B |
| Memory limit: | 1536MB |
| Cluster: | Cube (Intel G860) |
| Languages: | All except: ASM64 |
| Resource: | LCPC 2012 |
hide comments
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2013-08-05 19:39:24 ROHIT KUMAR
aftr 6 back-2-back WA---->"AC" in 0.02s:) |
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2013-08-05 15:19:33 chk
after 4 WAs finally removed from TODO list :D |
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2013-08-03 13:53:08 LeppyR64
Confirmed Constraints: (Verified with AC C program using Assert) 0 <= X <= 2*10^3 (Accurate) 0 < N <= 10^5 (Accurate) 0 <= C[i] < 10^3 (Inaccurate, C[i] can be 1000) 0 <= C[i] <= 10^3 (Accurate) Last edit: 2013-07-24 13:14:22 |
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2013-07-14 04:45:03 BLANKRK
AC...:) 1 runtym error jus due to wrong constraints........ |
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2013-07-04 08:34:23 Viktor Fonic
Here's a test case that gave me headaches: 1 5 5 2 3 4 5 6 Output should be: 1. 1 Last edit: 2013-07-04 08:34:32 |
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2013-06-09 14:00:23 Ouditchya Sinha
@Rajarshi Sarkar : Thank you for the insightful test case. :) |
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2013-05-17 08:44:37 shiva_hellgeek
MY 150th problem on spoj. :) |
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2013-04-28 10:52:52 Rajarshi Sarkar
Numbers can be same.A free test case from my side (as the description is not very clear) Input 5 4 4 2 2 2 2 Output 6 Both %lld or %d does the work. Last edit: 2013-04-28 11:03:30 |
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2013-04-26 02:04:46 Spar!k
can be solved in n*logn+n |
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2013-04-25 23:13:19 Eduardo Nunes
nice one, got 2 WAs just because I thought each number would be different ^_^ easy one with map |
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