3 1 2 4
0 1 9
明显的搓排公式
#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
const int mod = 1000000007;
int main()
{
int t,n;
__int64 a[200] = {0,0,1},i,j;
for(i = 3; i<=100; i++)
a[i] = ((a[i-1]+a[i-2])%mod)*(i-1)%mod;
scanf("%d",&t);
while(t--)
{
scanf("%d",&n);
printf("%I64d\n",a[n]);
}
return 0;
}
HDU4535:吉哥系列故事——礼尚往来(错牌公式),布布扣,bubuko.com
原文:http://blog.csdn.net/libin56842/article/details/20072191