hdu--5019--开始参加bc了

 1 #include <iostream>
 2 #include <set>
 3 #include <algorithm>
 4 using namespace std;
 5 
 6 typedef long long LL;
 7 set<LL>s;
 8 
 9 void solve( LL x , LL y )
10 {
11     for( LL i = 1 ; i<=y/i && i<=x ; i++ )
12     {
13         if( x%i ==0 && y%i ==0 )
14         {
15             s.insert(i);
16         }
17         if( x%(y/i)==0 )
18         {
19             s.insert(y/i);
20         }
21     }
22 }
23 
24 int main()
25 {
26     cin.sync_with_stdio(false);
27     int t , cnt;
28     LL x , y , k , temp , size;
29     cin >> t;
30     while( t-- )
31     {
32         s.clear();
33         cnt = 0;
34         set<LL>::iterator it;
35         cin >> x >> y >> k;
36         if( x>y )
37         {
38             swap(x,y);
39         }
40         solve(x,y);
41         size = s.size();
42         if( size<k )
43             cout << -1 << endl;
44         for( it = s.begin() ; it!=s.end() ; it++ )
45         {
46             ++ cnt;
47             if( cnt==size-k+1 )
48                 cout << *it << endl;
49         }
50     }
51     return 0;
52 }

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <vector>
 4 using namespace std;
 5 
 6 typedef long long LL;
 7 vector<LL> ve_left;
 8 vector<LL> ve_right;
 9 
10 void solve( LL x , LL y )
11 {
12     for( LL i = 1 ; i<=y/i && i<=x ; i++ )
13     {
14         if( y%i == 0 )
15         {
16             if( x%i==0 )
17             {
18                 ve_left.push_back(i);
19             }
20             if( y/i<=x && x%(y/i)==0 && i!=y/i )
21             {
22                 ve_right.push_back(y/i);
23             }
24         }
25     }
26 
27 }
28 
29 int main()
30 {
31     cin.sync_with_stdio(false);
32     int t;
33     LL x , y , k , Size , Size1 , Size2;
34     cin >> t;
35     while(t--)
36     {
37         ve_left.clear();
38         ve_right.clear();
39         cin >> x >> y >> k;
40         if( x>y )
41             swap( x , y );
42         solve( x , y );
43         Size1 = ve_left.size();
44         Size2 = ve_right.size();
45         Size = Size1 + Size2;
46         if( Size<k )
47             cout << -1 << endl;
48         else
49         {
50             if( Size2>=k )
51             {
52                 cout << ve_right[k-1] <<endl;
53             }
54             else
55             {
56                 k -= Size2;
57                 cout << ve_left[Size1-k] << endl;
58             }
59         }
60     }
61     return 0;
62 }

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <vector>
 4 using namespace std;
 5 
 6 typedef long long LL;
 7 vector<LL> ve;
 8 
 9 LL gcd( LL x , LL y )
10 {
11     return y%x == 0 ? x : gcd( LL(y%x) , x );    
12 }
13 
14 void solve( LL x , LL y , LL z )
15 {
16     for( LL i = 1 ; i<=z/i ; i++ )
17     {
18         if( z%i==0 )
19         {
20             ve.push_back(i);
21             if( i!=z/i )
22                 ve.push_back(z/i);        
23         }
24     }
25 }
26 
27 int main()
28 {
29     cin.sync_with_stdio(false);
30     int t;
31     LL x , y , k , z , Size;
32     cin >> t;
33     while(t--)
34     {
35         ve.clear();
36         cin >> x >> y >> k;
37         if( x>y )
38             swap( x , y );
39         z = gcd(x,y);
40         solve( x , y , z );
41         Size = ve.size();
42         if( Size<k )
43             cout << -1 << endl;
44         else
45         {
46             sort( ve.begin() , ve.end() );
47             cout << ve[Size-k] << endl; 
48         }
49     }
50     return 0;
51 }