10230. 「一本通 6.6 练习 1」牡牛和牝牛

#include<algorithm>
#include<bitset>
#include<complex>
#include<deque>
#include<exception>
#include<fstream>
#include<functional>
#include<iomanip>
#include<ios>
#include<iosfwd>
#include<iostream>
#include<istream>
#include<iterator>
#include<limits>
#include<list>
#include<locale>
#include<map>
#include<memory>
#include<new>
#include<numeric>
#include<ostream>
#include<queue>
#include<set>
#include<sstream>
#include<stack>
#include<stdexcept>
#include<streambuf>
#include<string>
#include<typeinfo>
#include<utility>
#include<valarray>
#include<vector>
#include<cstring>
using namespace std;
#define MAXE 400010
#define ll long long 
inline ll read(){
    char ch=getchar();ll res=0,f=1;
    while(ch<'0'ch>'9'){if(ch=='-') f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') res=res*10+ch-'0',ch=getchar();
    return res*f;
}
void write(ll x){
    if(x<0) putchar('-'),x=-x;
    if(x<10) putchar(x+'0');
    else{
        write(x/10);
        putchar(x%10+'0');
    }
}
ll f[100010],sum[100010];
ll n,k;
int main(){
    n=read();k=read();
    fill(f,f+100001,1);
    for(ll i=1;i<=n;i++){
        if(i>k){
            f[i]+=sum[i-k-1];
            f[i]%=5000011;
        }
        sum[i]=sum[i-1]+f[i];
        sum[i]%=5000011;
    }
    write(sum[n]+1);putchar('\n');
    return 0;
}