牛客比赛暂存

#include<bits/stdc++.h>
using namespace std;
#define int long long
int factorial_recursion( int n )
{
    if( n<=0 )
    {
        return 1;
    }
    else
    {
        return n * factorial_recursion( n-1 );
    }
}
signed main()
{
    int n,m,p;
    cin>>n>>m>>p;
    if(m==0) 
    {
        if(p==1)
        {
            cout<<"Yes!\n";
        }
        else
            cout<<"No!\n";
    }
    else if(m==1)
    {
        if(p==n)
            cout<<"Yes!\n";
        else
            cout<<"No!\n";
    }
    else
    {
        p=p*factorial_recursion(m);
        for(int i=n;i>=n-m+1;--i)
        {
            if(p%i==0) p/=i;
            else
            {
                cout<<"No!\n";
                break;
            }
        }
        cout<<"Yes!\n";
    }
}