HDU2519:新生晚会

 1 #include <iostream>
 2 
 3 using namespace std;
 4 int a,b;
 5 double zh(int a,int b)
 6 {
 7     int up=1,down=1;
 8     for(int i=1;i<=b;i++)
 9     {up=up*a;a--;}
10     for(int i=1;i<=b;i++)
11     down=down*i;
12     return up/down;
13 }
14 
15 int main()
16 {
17     int i;
18     cin>>i;
19     while(i--)
20     {
21         cin>>a>>b;
22         cout<<zh(a,b)<<endl;
23     }
24     return 0;
25 }

 1 #include <iostream>
 2 #include <stdio.h>
 3 using namespace std;
 4 long long a,b;
 5 double zh(long long a,long long b)
 6 {
 7     double ans=1.0;
 8     long long j=b;
 9     while(j--)
10     {
11         ans=ans*a/b;
12         a--;b--;
13     }
14     return ans;
15 }
16 
17 
18 int main()
19 {
20     int n;
21     cin>>n;
22     while(n--)
23     {
24         cin>>a>>b;
25         cout<<zh(a,b)<<endl;
26     }
27     return 0;
28 }

#include <iostream>
#include <stdio.h>
using namespace std;
long long a,b;
double zh(long long a,long long b)
{
    double ans=1.0;
    long long j=b;
    while(j--)
    {
        ans=ans*a/b;
        a--;b--;
    }
    return ans;
}


int main()
{
    int n;
    cin>>n;
    while(n--)
    {
        cin>>a>>b;
       printf("%.0lf\n",zh(a,b));

    }
    return 0;
}