#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=20+10;
int n,ans;
char a[N][N];
bool v[N];
void dfs(int step){
	if(step==n+1){
		ans++;
		return;
	}
	for(int i=1;i<=n;i++){
		if(a[step][i]=='1'&&!v[i]){
			v[i]=1;
			dfs(step+1);
			v[i]=0;
		}
	}
}
signed main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cin>>a[i][j];
		}
	}
	dfs(1);
	cout<<ans;
    return 0;
}

#include #include <math.h> #include <string.h> #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include <complex.h> #include <fenv.h> #include <inttypes.h> #include <stdbool.h> #include <stdint.h> #include <tgmath.h> const int N=20+10; using namespace std; int n,ans; char a[N][N]; bool v[N]; void dfs(int s) { if(sn+1) { ans++; return ; } for(int i=1;i<=n;i++) { if(a[s][i]'1'&&!v[i]) { v[i]=1; dfs(s+1); v[i]=0; } } } signed main() { cin>>n; for(int i=1;i<=n;i++) for(int j=1;j<=n;j++) cin>>a[i][j]; dfs(1); cout<<ans; return 0; }

#include<iostream> 
using namespace std; 
const int N = 20 + 10; 
const int INF = 0x3f3f3f; 
int ans,n; 
char a[N][N]; 
bool v[N]; 
void dfs(int step)
{ 
    if(step == n + 1)
	{ 
	    ans++; 
		return; 
	} 
	for(int i = 1;i <= n;i++)
	{ 
	    if(a[step][i] == '1' && !v[i])
		{ 
		    v[i] = 1; 
			dfs(step + 1); 
			v[i] = 0; 
		} 
	} 
} 
int main(){ 
    cin >> n; 
	for(int i = 1;i<=n;i++){ 
	    for(int j = 1;j<=n;j++){ 
		    cin >> a[i][j]; 
		} 
	} 
	dfs(1); 
	cout << ans;
	return 0; 
	}

#include using namespace std; const int N = 20 +10; const int INF=0x3f3f3f; int ans,n; char a[N][N]; bool v[N]; void dfs(int step){ if(step == n + 1){ ans++; return; } for(int i = 1;i<=n;i++){ if(a[step][i] == '1' && !v[i]){ v[i] = 1; dfs(step+1); v[i] = 0; } } } int main(){ cin>>n; for(int i = 1;i<=n;i++){ for(int j = 1;j<=n;j++){ cin>>a[i][j]; } } dfs(1); cout<<ans; }

#include<bits/stdc++.h> using namespace std;

const int MAXN = 25; int n, ans; char arr[MAXN][MAXN]; bool v[MAXN];

void dfs(int step) { if (step == n + 1) { ans++; return; } for (int i = 1; i <= n; i++) { if (arr[step][i] == '1' && !v[i]) { v[i] = 1; dfs(step + 1); v[i] = 0; } } }

int main() { cin >> n; for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { cin >> arr[i][j]; } }

dfs(1);
cout << ans << endl;
return 0;

}