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TIP1 - Totient in permutation (easy) |
In number theory, Euler's totient (or PHI function), is an arithmetic function that counts the number of positive integers less than or equal to a positive integer N that are relatively prime to this number N.
That is, if N is a positive integer, then PHI(N) is the number of integers K for which GCD(N, K) = 1 and 1 ≤ K ≤ N. We denote GCD the Greatest Common Divisor. For example, we have PHI(9)=6.
Interestingly, PHI(87109)=79180, and it can be seen that 87109 is a permutation of 79180.
Input
The input begins with the number T of test cases in a single line. In each of the next T lines there are an integer M.
Output
For each given M, you have to print on a single line the value of N, for which 1 < N < M, PHI(N) is a permutation of N and the ratio N/PHI(N) produces a minimum. If there's several answers output the greatest, or if need, "No solution." without quotes. Leading zeros are not allowed for integers greater than 0.
Example
Input: 3 22 222 2222 Output: 21 63 291
Explanations : For the first case, in the range ]1..22[, the lonely number n for which phi(n) is in permutations(n) is 21, (we have phi(21)=12). So the answer is obviously 21. For the second case, in the range ]1..222[, there's two numbers n for which phi(n) is in permutations(n), we have phi(21)=12 and phi(63)=36. But as 63/36 is equal to 21/12, we're taking the greater : 63. For the third case, in the range ]1..2222[, there's four numbers n for witch phi(n) is in permutations(n), phi(21)=12, phi(63)=36, phi(291)=192 and phi(502)=250. Within those solutions 291/192 is the minimum, we output 291.
Constraints
1 < T < 10^5 1 < M < 10^7
Code size limit is 10kB ; less than 500B of python3 code can get AC under 2s. After that you may try TIP2. @Speed addicts : my C code ran in 0.02s, and my fastest python3.2 code ran in 1.21s, (0.90s in py2.7)
Edit 2017-02-11, after compiler updates. My old C code ends in 0.00s, my old Python code ends in 0.05s !!!
Added by: | Francky |
Date: | 2013-01-06 |
Time limit: | 1.399s |
Source limit: | 10000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 |
Resource: | Extension of Project Euler n°### |
hide comments
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2015-07-12 13:30:47 Maroof
@FRANCKY do I have a lot of WAs in my last submission? For small input, you have lot of WA, for bigger ones, it seems OK. I just gave a quick look. Have fun. Last edit: 2015-07-12 13:52:02 |
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2015-07-02 05:36:33 [Lakshman]
AC now. A small bug and unlimited WA. =(Francky)=> Well done, TIP2 is waiting for you now. TIP3 is still broken [:sad]. There's other bugs with higher priority... -(Lakshman)-> @Francky can you please have a look at my TIP2 submission. Thanks. Last edit: 2015-07-03 11:18:23 |
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2015-01-30 07:53:48 [Lakshman]
@Francky Can you please check my code getting WA, I have checked several test cases with my brute force code and getting correct answer. --Francky--> Check again your brute force. You have some good answers. Last edit: 2015-01-30 08:04:15 |
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2014-10-30 10:17:54 Harry Mathis
I get always a runtime error (NZEC) with my java code, but i have no idee what i'm doing wrong? Is it possible, that the input numbers are Strings? I expect integers. --ans(Francky)--> Input is well formatted. I don't read Java, but I can give you a copy of the error : Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at Main. Could not find the main class: Main. Program will exit. @Francky: Your answer is very helpful. Thanx a lot. --ans(Francky)--> You're welcome. Last edit: 2014-10-30 22:29:23 |
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2014-05-19 14:39:22 Flago
"No solution" != "No solution." I hate those stupid mistakes ! |
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2013-06-03 15:46:05 :p
some more test cases please, getting wrong answer..!! :( |
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2013-04-09 23:51:10 abdelkarim
trying Last edit: 2013-04-09 23:55:45 |
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2013-03-11 11:28:35 (Tjandra Satria Gunawan)(曾毅昆)
wow, you break my record, i'm sure your I/O is faster than mine :-p |
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2013-03-11 10:40:28 Francky
Congratulations to Michael K. for having "solved" correctly the two bottlenecks and taken a good first place. |