代码

#include<bits/stdc++.h>
#define For(i,j,k) for(int i=j;i<=k;++i)
using namespace std;
int read(){
	int x=0,l=1; char ch=getchar();
	while(!isdigit(ch)) {if (ch=='-') l=-1; ch=getchar();}
	while(isdigit(ch)) x=x*10+(ch^48),ch=getchar();
	return x*l;
}
const int mo=998244353;
int a[11]; long long h[10005];
int main(){
	int _=read(),n; int cnt,s,ans;
	h[0]=h[1]=1;
	For(i,2,10000){
		For(j,0,i-1) h[i]+=h[j]*h[i-j]%mo;
		h[i]=h[i]%mo;
	}
	while(_--){
		n=read(); ans=0;
		For(i,1,n) a[i]=read();
		if (n<=10){
		while(next_permutation(a+1,a+1+n)){
			cnt=s=0;
			For(i,1,n) s+=abs(a[i]-i); s/=2;
			For(i,1,n-1)
				For(j,i+1,n) if (a[i]>a[j]) ++cnt;
			if (cnt==s) ++ans;
		}
		printf("%d\n",ans);
		}
		printf("%d\n",h[n+1]-1);
	}
	return 0;
}

评测结果