HDU 5459 Jesus Is Here (递推)

#include<bits/stdc++.h>
using namespace std;

#define PB push_back
#define MP make_pair
#define fi first
#define se second

typedef long long ll;


const int N = 201314+5;
ll f[N], c[N], l[N], g[N];
const int Mod =  530600414;

inline ll f21(int i) { return f[i]-f[i-2]-f[i-1]; }
inline ll ccl(int i,int j,int k) { return c[i]*c[j]%Mod*l[k]; }
inline ll f12(int i) { return g[i-2]+f21(i-1)+ccl(i-3,i-2,i-2); }//用到i-3

//#define LOCAL
int main()
{
#ifdef LOCAL
    freopen("in.txt","r",stdin);
#endif
    l[1] = 1; l[2] = 2;
    l[3] = 3; l[4] = 5;
    c[3] = 1; c[4] = 1;
    g[3] = 3; g[4] = 5;
    for(int i = 5; i <= 201314; i++){
        l[i] = (l[i-1]+l[i-2])%Mod;
        c[i] = (c[i-1]+c[i-2])%Mod;
        f[i] = (f[i-1]+f[i-2]+g[i-2]+ccl(i-2,i-2,i-3)+f12(i-1)+Mod)%Mod;//用到i-4,所以从5开始
        g[i] = (g[i-1]+g[i-2]+ccl(i-1,i-1,i-2)+ccl(i-2,i-2,i-1)+f12(i)+f21(i)+ccl(i-2,i-1,i))%Mod;//用到f[i]和l[i],所以f[i]l[i]在前面
    }
    int T, kas = 0; scanf("%d",&T);
    while(T--){
        int n; scanf("%d",&n);
        printf("Case #%d: %I64d\n",++kas,f[n]);
    }
    return 0;
}