codeforces Upgrading Array

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <map>
 4 #include <set>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 set<int>q;
 9 int n,m;
10 int a[50010],b[50010];
11 int g[50010];
12 
13 int gcd(int a,int b)
14 {
15     return b==0?a:gcd(b,a%b);
16 }
17 
18 int Get_num(int x)
19 {
20     int ans=0;
21     map<int,int>p;
22     for(int j=2; j*j<=x; j++)
23     {
24         if(x%j==0)
25         {
26             while(x%j==0)
27             {
28                 p[j]++;
29                 x/=j;
30             }
31         }
32     }
33     if(x>1) p[x]++;
34     map<int,int>::iterator it;
35     for(it=p.begin(); it!=p.end(); it++)
36     {
37         if(q.find(it->first)==q.end()) ans+=it->second;
38         else ans-=it->second;
39     }
40     return ans;
41 }
42 
43 int main()
44 {
45 
46     scanf("%d%d",&n,&m);
47     for(int i=1; i<=n; i++)
48     {
49         scanf("%d",&a[i]);
50     }
51     for(int j=1; j<=m; j++)
52     {
53         scanf("%d",&b[j]);
54         q.insert(b[j]);
55     }
56     int ans=0;
57     for(int i=1; i<=n; i++)
58     {
59        ans+=Get_num(a[i]);
60     }
61     for(int i=1; i<=n; i++)
62     {
63         if(i==1) g[i]=a[i];
64         else g[i]=__gcd(g[i-1],a[i]);
65     }
66     int c=1;
67     for(int i=n; i>=1; i--)
68     {
69         int h=g[i]/c;
70         int s=Get_num(h);
71         if(s<0)
72         {
73             ans-=s*i;
74             c*=h;
75         }
76     }
77     printf("%d\n",ans);
78     return 0;
79 }