1015. reversible PRIMES (20) -- Pat (Advanced Level) practise

Question information:

1015. reversible PRIMES (20) Time Limit 400 MS
The memory limit is 32000 kb.
Code length limit: 16000 B
Criterion author Chen, Yue

AReversible primeIn any number system is a prime whose "reverse" in that number system is also a prime. For example in the decimal system 73 is a reversible prime because its reverse 37 is also a prime.

Now given any two positive integers n (<10^{5) and D (1 <D <= 10), you are supposed to tell if n is a reversible prime with Radix D.}

Input specification:

The input file consists of several test cases. Each case occupies a line which contains two integers n and D. The input is finished by a negative n.

Output specification:

For each test case, print in one line "yes" if n is a reversible prime with Radix D, or "no" if not.

Sample input:

73 1023 223 10-2

Sample output:

YesYesNo

The Code is as follows:

# Include <stdio. h> # include <math. h> int is_prime (int n) // prime number judgment {if (1 = N) return 0; int end = SQRT (double) N ); for (INT I = 2; I <= end; ++ I) {If (N % I = 0) return 0;} return 1;} int Re (int, int Radix) // returns the value of {int arr [20], Loc = 0, S = 0, base = 1; while () {arr [loc ++] = A % Radix; A/= Radix;} while (loc --) {S + = arr [loc] * base; base * = Radix ;} return s;} int main () {int A, B; while (scanf ("% d", & A) & a> 0) {scanf ("% d ", & B); If (is_prime (a) & is_prime (RE (a, B) printf ("Yes \ n "); elseprintf ("NO \ n");} return 0 ;}

1015. reversible PRIMES (20) -- Pat (Advanced Level) practise