HDU 1431 素数回文(打表)

#include <stdio.h>
#include <stdio.h>
using namespace std;
bool a[9989900];
int prime[1005];
void set()
{
int i,j;
for(i = 2; i<=9989899; i+=2)
a[i] = true;
for(i = 3; i<=3161; i++){
if(a[i])
continue;
for(j = i+i; j<=9989899; j+=i)
a[j] = true;
}
}
int huiwen(int n)
{
int a = 0,b = n;
int r;
while(b){
r = b%10;
a = a*10+r;
b/=10;
}
if(a == n)
return 1;
return 0;
}
int main()
{
int n,m,i,k = 2;
set();
prime[0] = 5;
prime[1] = 7;
for(i = 11; i<=9989899; i+=2){
if(!a[i] && huiwen(i))
prime[k++] = i;
}
while(~scanf("%d%d",&n,&m)){
for(i = 0; i<k; i++){
if(prime[i]<n)
continue;
else if(prime[i]>m)
break;
else
printf("%d\n",prime[i]);
}
printf("\n");
}
return 0;
}