OJ-Problems-Source/HDOJ/5136_autoAC.cpp

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#include<cstdio>
#include<ctype.h>
#include<algorithm>
#include<iostream>
#include<cstring>
#include<vector>
#include<cstdlib>
#include<stack>
#include<cmath>
#include<queue>
#include<set>
#include<map>
#include<ctime>
#include<string.h>
#include<string>
#include<sstream>
#include<bitset>
using namespace std;
#define ll __int64
#define ull unsigned long long
#define eps 1e-8
#define NMAX 1000000005
#define MOD 1000000007
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define PI acos(-1)
template<class T>
inline void scan_d(T &ret)
{
char c;
int flag = 0;
ret=0;
while(((c=getchar())<'0'||c>'9')&&c!='-');
if(c == '-')
{
flag = 1;
c = getchar();
}
while(c>='0'&&c<='9') ret=ret*10+(c-'0'),c=getchar();
if(flag) ret = -ret;
}
ll dp[100005],sum[100005];
void cal()
{
ll a = 3,b = MOD-2,ret = 1;
while(b)
{
if(b&1) ret = ret*a%MOD;
a = a*a%MOD;
b >>= 1;
}
cout<<ret<<endl;
}
int main()
{
dp[1] = dp[2] = 1;
sum[0] = 1;
sum[1] = 2;
ll tmp = 1;
for(int i = 3; i <= 100000; i++)
{
if(i%2)
{
ll a = ((tmp*(tmp-1LL+MOD)%MOD*(tmp-2LL+MOD)%MOD)*166666668LL%MOD + tmp*(tmp-1LL+MOD)%MOD + tmp)%MOD;
dp[i] = (sum[i/2-1]*((tmp*(tmp-1LL+MOD)%MOD)*500000004LL%MOD+tmp)%MOD+a)%MOD;
}
else
{
ll a = tmp*sum[i/2-2]%MOD;
tmp = (tmp*(tmp-1LL+MOD)%MOD*500000004LL%MOD+tmp+a)%MOD;
dp[i] = (tmp*(tmp-1LL+MOD)%MOD*500000004LL%MOD+tmp)%MOD;
sum[i/2] = (sum[i/2-1]+tmp)%MOD;
}
}
int n;
while(~scanf("%d",&n) && n)
{
printf("%I64d\n",dp[n]);
}
return 0;
}