UVALive 5971

Problem J Permutation Counting

Dexter considers a permutation of first N natural numbers good if it doesn't have x and x+1 appearing consecutively, where (1 ≤ x < N)  For example, for N=3 , all goodpermutations are:

1. {1, 3, 2}

2.{2, 1, 3}

3.{3, 2, 1}

Input

Input starts with an integer T (≤ 10000 , denoting the number of test cases.Each

case starts with a line containing an integer N (1 ≤ N ≤ 106)

.

Output

For each case, print the case number and the number ofgoodpermutations

modulo1000 000 007

.

Sample Input

Output for Sample Input

3

2

3

5

Case 1: 1

Case 2: 3

Case 3: 53

#include <map>
#include <set>
#include <list>
#include <cmath>
#include<cctype>
#include <ctime>
#include <deque>
#include <stack>
#include <queue>
#include <cstdio>
#include <string>
#include <vector>
#include<climits>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define LL long long
#define PI 3.1415926535897932626
using namespace std;
int gcd(int a, int b) {return a % b == 0 ? b : gcd(b, a % b);}
#define MAXN 1000005
#define MOD 1000000007
LL ans[MAXN],tmp[MAXN];
void init()
{
    ans[1]=1;ans[2]=1;
    for (int i=3;i<MAXN;i++)
       {
           ans[i]=((i-1)*ans[i-1])+(i-2)*ans[i-2];
           ans[i]%=MOD;
       }
}
int main()
{
    init();
    int T;int kase=1;
    scanf("%d",&T);
    while (T--)
    {
        int N;
        scanf("%d",&N);
        printf("Case %d: %lld
",kase++,ans[N]);
    }
    return 0;
}