F(N)
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3202 Accepted Submission(s): 1106
Problem Description
Giving the N, can you tell me the answer of F(N)?
Input
Each test case contains a single integer N(1<=N<=10^9). The input is terminated by a set starting with N = 0. This set should not be processed.
Output
For each test case, output on a line the value of the F(N)%2009.
Sample Input
1 2 3 0
Sample Output
1 7 20
知识点：鸽巢原理、递推
#include<iostream>
using namespace std;
int main()
{ int a[5000];
a[1]=1;
a[2]=7;
int i,n;
for(i=3;i<=4018;i++)
{a[i]=a[i-2]+3*i*(i-1)+1;
if(a[i]>2009) a[i]=a[i]%2009;}
while(cin>>n,n)
{
cout<<a[n%4018]<<endl;
}
return 0;
}
