|VIRTUAL JUDGE||Recent Contest||F.A.Qs||Forum||Home||ProblemSet||Status||Ranklist||Contest||Login||Register||Exam|
Certain cryptographic algorithms make use of big prime numbers. However, checking whether a big number is prime is not so easy. Randomized primality tests exist that offer a high degree of confidence of accurate determination at low cost, such as the Fermat test. Let a be a random number between 2 and n - 1, where n is the number whose primality we are testing. Then, n is probably prime if the following equation holds: an mod n = a If a number passes the Fermat test several times, then it is prime with a high probability. Unfortunately, there is bad news. Certain composite numbers (non-primes) still pass the Fermat test with every number smaller than themselves. These numbers are called Carmichael numbers. Write a program to test whether a given integer is a Carmichael number.
The input will consist of a series of lines, each containing a small positive number n ( 2 < n < 65, 000). A number n = 0 will mark the end of the input, and must not be processed.
For each number in the input, print whether it is a Carmichael number or not as shown in the sample output
1729 17 561 1109 431 0
The number 1729 is a Carmichael number. 17 is normal. The number 561 is a Carmichael number. 1109 is normal. 431 is normal.
한국어 中文 English
All Copyright Reserved 2008-2010 SDIBT TEAM
GPL2.0 2003-2010 HUSTOJ Project TEAM
Anything about the Problems, Please Contact Admin:admin