9528 潜伏2

gistfile1.cpp

#include <stdio.h>
#include <string.h>
#include <math.h>
int main()
{
    int prime[100];
    for (int i = 10; i <= 99; i++)
    {
        int f = 1;
        for (int j = 2; j <= sqrt(i); j++)
            if (i % j == 0) {f = !f; break;}
        prime[i] = f;
    }
    //for (int i = 10; i <= 99; i++) if (prime[i]) printf("%d ",i);
    char s[100005];
    int flag[100005];
    gets(s);
    int n = strlen(s);
    flag[n] = -1;
    int elem = -1;
    for (int i = n - 2; i >= 0; i--)
    {
        int tmp = (s[i] - 48)*10 + s[i + 1] - 48;
        if (prime[tmp] == 1) elem = tmp;
        flag[i + 1] = elem;
    }
    int m,v;
    scanf("%d",&m);
    for (int i = 1; i < m; i++)
    {
        scanf("%d",&v);
        printf("%d\n",flag[v]);
    }
    scanf("%d",&v);
    printf("%d",flag[v]);

}