10:判决素数个数

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<cmath>
 5 using namespace std;
 6 char a[10001];
 7 int b[10001];
 8 int maxn=-1;
 9 char ans=0;
10 int beginn;
11 int endn;
12 int now;
13 int tot;
14 int flag=0;
15 int main()
16 {
17     int x,y;
18     cin>>x>>y;
19     for(int i=min(x,y);i<=max(x,y);i++)
20     {
21         flag=0;
22         for(int j=2;j<=sqrt(i);j++)
23         {
24             if(i%j==0)
25             {
26                 flag=1;
27                 break;
28             }
29             
30         }
31         if(flag==0)
32         tot++;
33     }
34     if(min(x,y)==1)
35     cout<<tot-1;
36     else cout<<tot;
37     return 0;
38 }