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POWTOW - Power Tower City |
You are living in a city build entirely of power towers such as 3^3^3 and 10^10^10^10. To enter a building you must type the last 9 digits of the number represented by the tower, written in decimal form, on a keypad next to the main entrance. You are not sharp enough at mental maths, but you can write a handy program to bring along in your pocket.
A power tower is defined as repeated exponentiation. We write this using Knuth's up-arrow notation as: e↑↑a = e^e^...^e (a terms). Remember that ^ (exponentiation) is right associative. For example: 2↑↑4 = 2^2^2^2 = 2^(2^(2^2)) = 2^2^4 = 2^16 = 65536, and 3↑↑1 = 3. The value of a tower of height 0 is 1.
Input
The first line contains integer C in [0..1000], the number of test cases.
Then follows C lines, each with integers e,a in [0..2147483647]. (non-negative 32-bit integers).
Output
For each testcase output e↑↑a, or if the output has more than 9 digits, output "..." and then the last 9 digits.
Example
Input: 3 0 0 2 5 993306745 75707320 Output: 1 ...719156736 ...884765625
Added by: | Thomas Dybdahl Ahle |
Date: | 2011-11-21 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
hide comments
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2012-04-10 03:01:43 suhang
@Thomas Dybdahl Ahle Can you give me some test i'm getting WA? T_T |
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2012-04-09 19:34:06 pulkit
@Thomas: My code seems to work correctly.. Can't really find any corner case... A hint would be useful... |
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2012-02-07 11:36:05 Anirvan Sarkar
@Thomas Dybdahl Ahle: Thanks for pointing out my mistake. It helped me to find the bug in my code after many WA. |
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2012-02-04 00:30:50 Thomas Dybdahl Ahle
@Anirvan Sarkar: You fail "2 20" @Marin Tomic: You fail "0 1" @Santiago Palacio: I have made the problem description more clear. |
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2012-02-04 00:19:52 Santiago Palacio
Yes, i know you can deduce it from that, but what i say is that with problems like this, it's not always that obvious and should be more explicit. |
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2012-02-04 00:19:52 Mitch Schwartz
@Santiago: 2^2^2^2 = 2^2^4 = 2^16 = 65536 is unambiguous. You can notice that ((2^2)^2)^2 would make 256. |
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2012-02-04 00:19:52 Anirvan Sarkar
@Thomas Dybdahl Ahle Can you tell me for which test case i'm getting WA? |
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2012-02-04 00:19:52 Santiago Palacio
It's 2^(2^(2^2))) right? (I think the problem statement is not fully clear about it, as it could be (((2^2)^2)^2). |
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2012-02-04 00:19:52 Thomas Dybdahl Ahle
@numerix: np. But I'm wondering if the bug shows that your method isn't strong enough for general mods? |
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2012-02-04 00:19:52 Thomas Dybdahl Ahle
Hi numerix, you are right. Test data was wrong for 0||(2n). It's fixed now. Thank you. I can tell you that you still report "10 3" as "...000000001" which is clearly wrong. Last edit: 2011-11-23 22:01:38 |