BZOJ 3398: [Usaco2009 Feb]Bullcow 牡牛和牝牛 水题~

Code: 

#include <cstdio>   
#define N 100004 
#define mod 5000011 
#define setIO(s) freopen(s".in", "r" , stdin)      
using namespace std;
int f[N][2];  
int main() 
{
    // setIO("input");  
    int n , k, i ; 
    scanf("%d%d", &n, &k);      
    f[1][0] = f[1][1] = 1;    
    for(i = 2; i <= n ; ++ i) 
    {   
        f[i][0] = (f[i - 1][0] + f[i - 1][1]) % mod; 
        if(i > k) f[i][1] = f[i - k][0];                       
        else f[i][1] = 1;    
    } 
    printf("%d\n", (f[n][0] + f[n][1]) % mod);    
    return 0; 
}