小黑跳地毯减肥（递推）

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 using namespace std;
 5 int a[1005];
 6 int solve(int n){
 7     if(n==1)
 8         return 0;
 9     else if(n==2)
10         return 2;
11     else if(n==3)
12         return 2;
13     else{
14         for( int i = 4; i <= n; i++ )
15             a[i] = (a[i-1]+2*a[i-2])%10000;
16     }
17     return a[n];
18 }
19 
20 int main(){
21     
22     int n;
23     a[1] = 0;
24     a[2] = 2;
25     a[3] = 2;
26     while(cin>>n&&n){
27         cout<<solve(n)<<endl;
28     }
29     return 0;
30 }