hdu 5459 Jesus Is Here 沈阳网赛

按照这个规律找出来的不断取模之下会得负数。需要(ans+mod)%mod，化为正数。

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define ll __int64
const ll mod=530600414;
const int maxn=201399;
ll w[maxn],ans[maxn],num[maxn],len[maxn];
void init()
{
	int n=201318,i;
	len[1]=1;len[2]=2;
	for(i=3;i<=n;i++)
		len[i]=(len[i-1]+len[i-2])%mod;
	for(i=0;i<=4;i++)	ans[0]=0;
	num[0]=0;num[1]=0;num[2]=0;
	w[4]=3;w[3]=1;
	num[3]=1;num[4]=1;
	for(i=5;i<=n;i++)
	{
		ans[i]=((ans[i-1]+ans[i-2])%mod+
			((len[i-2]*num[i-2]%mod-w[i-2])%mod)*num[i-1]%mod+w[i-1]*num[i-2]%mod)%mod;
		num[i]=(num[i-1]+num[i-2])%mod;
		w[i]=(num[i-1]*len[i-2]%mod+(w[i-1]+w[i-2])%mod)%mod;
	}
}
int main()
{
	int i,j,n,t;
	init();
	while(scanf("%d",&t)==1)
	{
		int cas=1;
		while(t--)
		{
			scanf("%d",&n);
			printf("Case #%d: %I64d\n",cas++,(ans[n]+mod)%mod);
		}
	}
	return 0;
}