释放无限光明的是人心,制造无边黑暗的也是人心,光明和黑暗交织着,厮杀着,这就是我们为之眷恋又万般无奈的人世间。
A reversible prime in 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 (<105) 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 10
23 2
23 10
-2
Sample Output:
Yes
Yes
No
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <vector>
#include <ctime>
#include <cctype>
#include <bitset>
#include <utility>
#include <sstream>
#include <complex>
#include <iomanip>
#include<climits>//INT_MAX
//#include<bits/stdc++.h>
#define PP pair<ll,int>
#define inf 0x3f3f3f3f
#define llinf 0x3f3f3f3f3f3f3f3fll
#define dinf 1000000000000.0
#define PI 3.1415926
typedef long long ll;
using namespace std;
int const mod=1e9+7;
const int maxn=3e5+10;
queue<int>q;
int p[101100],n,d;
void init()
{
memset(p,0,sizeof p);
p[1]=1;
for(int i=2; i<=101000; i++)
{
if(p[i]==0)
{
for(int j=2; j*i<=101000; j++)
p[i*j]=1;
}
}
return ;
}
int main()
{
init();
while(~scanf("%d",&n))
{
if(n<0)
break;
scanf("%d",&d);
if(p[n]==1)
printf("No\n");
else
{
while(!q.empty())
q.pop();
int k=n;
while(k)
{
q.push(k%d);
k=k/d;
}
k=0;
while(!q.empty())
{
k=k*d+q.front();
q.pop();
}
if(p[k]==0)
printf("Yes\n");
else
printf("No\n");
}
}
return 0;
}