找规律 2015百度之星资格赛 1001 大搬家

题目传送门

/*
    找规律：题目真心读不懂，排列组合的题目
*/
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;

typedef long long ll;

const int MAXN = 1e6 + 10;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
ll dp[MAXN];

void solve(void)
{
    dp[1] = 1;    dp[2] = 2;
    for (int i=3; i<=1e6; ++i)
    {
        dp[i] = (dp[i-1] + (i - 1) * dp[i-2]) % MOD;
    }
}

int main(void)        //2015百度之星资格赛 1001 大搬家
{
    solve ();
    int t, cas = 0;
    scanf ("%d", &t);
    while (t--)
    {
        int n;    scanf ("%d", &n);
        printf ("Case #%d:
", ++cas);
        printf ("%I64d
", dp[n]);
    }

    return 0;
}


/*
2
1
3
*/