4.3w+
社区成员
1.
#include <iostream>
using namespace std;
int main()
{
int arr[20190355];
arr[1]=1;
arr[2]=1;
arr[3]=1;
for(int i=4;i<=20190324;i++){
arr[i]=arr[i-1]+arr[i-2]+arr[i-3];
arr[i]%=10000;
}
cout<<arr[20190324];
return 0;
}
2.
#include <iostream>
using namespace std;
bool check(int n){
for(int i=2;i<n;i++)
{
if(n%i==0)
return false;
}
return true;
}
int main()
{
int t=1,i=2;
while(t<=2019){
if(check(i))
t++;
i++;
}
cout<<i-1;
return 0;
}
3.
#include <iostream>
using namespace std;
int main()
{
int n;
cin>>n;
int t=n;
while(n>=3){
int k=n/3;
t+=k;
n-=k*3;
n+=k;
}
cout<<t;
return 0;
}
4.