1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cstring>
 4 #include<cmath>
 5 #include<iostream>
 6 using namespace std;
 7
 8 int n,ans=12;
 9 int a[12];
10 struct node {int t;int p[3000];}
11 b[12];
12
13 int mmin(int x,int y)
14 {   return x<y?x:y;  }
15 int com(int id,int x)
16 {
17     for (int i=1;i<=b[id].t;i++)
18       if (x%b[id].p[i]==0) return 0;
19     return 1;
20 }
21 void dfs(int id,int h)
22 {
23     int x=a[id];
24     if (id>n) {ans=mmin(ans,h); return;}
25     for (int i=1;i<=h;i++)
26       if (com(i,x))
27       {
28         int y=x,tt=b[i].t;
29         for (int j=2;j<=y;j++)//sqrt(y) wrong
30           if (y%j==0) y/=j, b[i].p[++b[i].t]=j;
31         dfs(id+1,h);
32         b[i].t=tt;
33       }
34     int y=x;
35     b[h+1].t=0;
36     for (int j=2;j<=y;j++)
37       if (y%j==0) y/=j, b[h+1].p[++b[h+1].t]=j;
38     dfs(id+1,h+1);
39 }
40 int main()
41 {
42     scanf("%d",&n);
43     for (int i=1;i<=n;i++)
44       scanf("%d",&a[i]);
45     dfs(1,0);
46     printf("%d",ans);
47     return 0;
48 }

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cstring>
 4 #include<iostream>
 5 using namespace std;
 6
 7 const int N=15;
 8 int n,ans;
 9 int a[N],b[N][N],t[N];
10
11 int mmin(int x,int y)
12 {   return x<y?x:y;  }
13 int gcd(int x,int y)
14 {   return (!y)?x:gcd(y,x%y);  }
15 bool addit(int x,int i)
16 {
17     for (int j=1;j<=t[i];j++)
18       if (gcd(x,b[i][j])!=1) return false;
19     return true;
20 }
21 void dfs(int x,int h)
22 {
23     if (x>n) {ans=mmin(h,ans);return;}
24     for (int i=1;i<=h;i++)
25       if (addit(a[x],i))
26       {
27         b[i][++t[i]]=a[x];
28         dfs(x+1,h);
29         t[i]--;
30       }
31     b[h+1][++t[h+1]]=a[x];
32     dfs(x+1,h+1);
33 }
34 int main()
35 {
36     scanf("%d",&n);
37     for (int i=1;i<=n;i++)
38       scanf("%d",&a[i]);
39     memset(t,0,sizeof(t));
40     ans=N;
41     dfs(1,0);
42     printf("%d\n",ans);
43     return 0;
44 }