Problem:
Score : 100 points

Problem Statement

There are N men and N women, both numbered 1, 2, \ldots, N.

For each i, j (1 \leq i, j \leq N), the compatibility of Man i and Woman j is given as an integer a_{i, j}.
If a_{i, j} = 1, Man i and Woman j are compatible; if a_{i, j} = 0, they are not.

Taro is trying to make N pairs, each consisting of a man and a woman who are compatible.
Here, each man and each woman must belong to exactly one pair.

Find the number of ways in which Taro can make N pairs, modulo 10^9 + 7.

Constraints

All values in input are integers.

1 \leq N \leq 21

a_{i, j} is 0 or 1.

Input

Input is given from Standard Input in the following format:

N
a_{1, 1} \ldots a_{1, N}
:
a_{N, 1} \ldots a_{N, N}

Output

Print the number of ways in which Taro can make N pairs, modulo 10^9 + 7.

Sample Input 1

3
0 1 1
1 0 1
1 1 1

Sample Output 1

3

There are three ways to make pairs, as follows ((i, j) denotes a pair of Man i and Woman j):

(1, 2), (2, 1), (3, 3)

(1, 2), (2, 3), (3, 1)

(1, 3), (2, 1), (3, 2)

Sample Input 2

4
0 1 0 0
0 0 0 1
1 0 0 0
0 0 1 0

Sample Output 2

1

There is one way to make pairs, as follows:

(1, 2), (2, 4), (3, 1), (4, 3)

Sample Input 3

1
0

Sample Output 3

0

Sample Input 4

21
0 0 0 0 0 0 0 1 1 0 1 1 1 1 0 0 0 1 0 0 1
1 1 1 0 0 1 0 0 0 1 0 0 0 0 1 1 1 0 1 1 0
0 0 1 1 1 1 0 1 1 0 0 1 0 0 1 1 0 0 0 1 1
0 1 1 0 1 1 0 1 0 1 0 0 1 0 0 0 0 0 1 1 0
1 1 0 0 1 0 1 0 0 1 1 1 1 0 0 0 0 0 0 0 0
0 1 1 0 1 1 1 0 1 1 1 0 0 0 1 1 1 1 0 0 1
0 1 0 0 0 1 0 1 0 0 0 1 1 1 0 0 1 1 0 1 0
0 0 0 0 1 1 0 0 1 1 0 0 0 0 0 1 1 1 1 1 1
0 0 1 0 0 1 0 0 1 0 1 1 0 0 1 0 1 0 1 1 1
0 0 0 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 0 0 1
0 1 1 0 1 1 0 0 1 1 0 0 0 1 1 1 1 0 1 1 0
0 0 1 0 0 1 1 1 1 0 1 1 0 1 1 1 0 0 0 0 1
0 1 1 0 0 1 1 1 1 0 0 0 1 0 1 1 0 1 0 1 1
1 1 1 1 1 0 0 0 0 1 0 0 1 1 0 1 1 1 0 0 1
0 0 0 1 1 0 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1
1 0 1 1 0 1 0 1 0 0 1 0 0 1 1 0 1 0 1 1 0
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 1 1 0 0 1
0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 0 0 1 1 0 1
0 0 0 0 1 1 1 0 1 0 1 1 1 0 1 1 0 0 1 1 0
1 1 0 1 1 0 0 1 1 0 1 1 0 1 1 1 1 1 0 1 0
1 0 0 1 1 0 1 1 1 1 1 0 1 0 1 1 0 0 0 0 0

Sample Output 4

102515160

Be sure to print the number modulo 10^9 + 7.

Solution in Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.io.*;
import java.io.IOException;
import java.lang.Thread.State;
import java.util.*;
//import javafx.util.Pair; 
//import java.util.concurrent.LinkedBlockingDeque;




    
  public class Main {
        
        public static long mod = (long)Math.pow(10, 9)+7 ;
        public static double epsilon=0.00000000008854;//value of epsilon
        public static InputReader sc = new InputReader(System.in);
        public static PrintWriter pw = new PrintWriter(System.out);
        
        public static ArrayList<ArrayList <Integer>> GetGraph(int n,int m){
            ArrayList<ArrayList <Integer>> g=new ArrayList<>();
            for(int i=0;i<n;i++){
                g.add(new ArrayList<>());
            }
            for(int i=0;i<m;i++){
                int t=sc.nextInt();
                int u=sc.nextInt()-1;
                int v=sc.nextInt()-1;
                g.get(u).add(v);
                if(t==0)
                g.get(v).add(u);
            }
            return g;
        }
        
        public static int find(int a,int p[]){
            if(a!=p[a]){
               p[a]=find(p[a], p);
            }
             return p[a];
        }
        public static void Union(int a,int b,int p[]){
            p[find(b, p)]=find(a, p);
        }
        public static long gcd(long a,long b){
            while(b>0){
                long t=b;
                b=a%b;
                a=t;
            }
            return a;
        }
        public static boolean dfs(ArrayList<ArrayList <Integer>> g,ArrayList<HashSet<Integer>> h,int u,int vis[]){
            vis[u]=1;
            boolean f=false;
            for(int i=0;i<g.get(u).size();i++){
                int v=g.get(u).get(i);
                if(vis[v]==1){

                }



                if(vis[v]==1){
                    if(h.get(v).contains(u)){
                        h.get(u).remove(v);
                    }
                    else f=true;
                }
                if(vis[v]==0)
                if(dfs(g, h,v, vis)){
                    if(h.get(v).contains(u)){
                        h.get(u).remove(v);
                    }
                    else f=true;
                }
                else{
                    if(h.get(v).contains(u)){
                        h.get(v).remove(u);
                    }
                }
            }
            vis[u]=2;
            return f;
        }
        public static long fun(int vis,int a[][],int n,long dp[][]){
            if(n<0)
            return 1;
            if(dp[n][vis]!=-1)
            return dp[n][vis];
            int l=a.length;
            dp[n][vis]=0;
            for(int i=0;i<l;i++){
                if(a[n][i]==1&&(vis&(1<<i))==0){
                    //vis|=(1<<i);
                    dp[n][vis]+=fun(vis|(1<<i), a, n-1,dp);
                    //vis^=(1<<i);
                    dp[n][vis]%=mod;
                }

            }
            return dp[n][vis];
        }
        
        
        public static void main(String[] args) {
            // code starts..
            int n=sc.nextInt();
            int a[][]=new int[n][n];
            for(int i=0;i<n;i++){
                for(int j=0;j<n;j++){
                    a[i][j]=sc.nextInt();
                }
            }
            long dp[][]=new long[n][(int)(Math.pow(2, 21)+1)];
            for(int i=0;i<n;i++){
                Arrays.fill(dp[i], -1);
            }
            pw.println(fun(0, a, n-1,dp));
                
                         
            // Code ends...
            pw.flush();
            pw.close();
        }
       
        public static Comparator<Integer[]> column(int i){
            return 
            new Comparator<Integer[]>() {
                @Override
                public int compare(Integer[] o1, Integer[] o2) {
                    return o1[i].compareTo(o2[i]);//for ascending
                    //return o2[i].compareTo(o1[i]);//for descending
                }
            };
        }
        public static Comparator<Pair> C(){
            return 
            new Comparator<Pair>() {
                @Override
                public int compare(Pair o1, Pair o2) {
                    return o2.le-o1.le;//for des
                }
            };
        }
        
        public static Comparator<Integer[]> pair(){
            return 
            new Comparator<Integer[]>() {
                @Override
                public int compare(Integer[] o1, Integer[] o2) {
                    int result=o1[0].compareTo(o2[0]);
                    if(result==0)
                    result=o1[1].compareTo(o2[1]);
                    return result;
                }
            };
        }
        
        public static String reverseString(String s){
            StringBuilder input1 = new StringBuilder(); 
            input1.append(s);  
            input1 = input1.reverse();
            return input1.toString();
        }
        public static int[] scanArray(int n){
            int a[]=new int [n];
            for(int i=0;i<n;i++)
            a[i]=sc.nextInt();
    
            return a;
        }
        public static long[] scanLongArray(int n){
            long a[]=new long [n];
            for(int i=0;i<n;i++)
            a[i]=sc.nextLong();
    
            return a;
        }
        public static String [] scanStrings(int n){
            String a[]=new String [n];
            for(int i=0;i<n;i++)
            a[i]=sc.nextLine();
    
            return a;
        }
        
    }
    
    class InputReader {
    
            private final InputStream stream;
            private final byte[] buf = new byte[8192];
            private int curChar, snumChars;
            private SpaceCharFilter filter;
    
            public InputReader(InputStream stream) {
                this.stream = stream;
            }
    
            public int snext() {
                if (snumChars == -1)
                    throw new InputMismatchException();
                if (curChar >= snumChars) {
                    curChar = 0;
                    try {
                        snumChars = stream.read(buf);
                    } catch (IOException e) {
                        throw new InputMismatchException();
                    }
                    if (snumChars <= 0)
                        return -1;
                }
                return buf[curChar++];
            }
    
            public int nextInt() {
                int c = snext();
                while (isSpaceChar(c)) {
                    c = snext();
                }
                int sgn = 1;
                if (c == '-') {
                    sgn = -1;
                    c = snext();
                }
                int res = 0;
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = snext();
                } while (!isSpaceChar(c));
                return res * sgn;
            }
    
            public long nextLong() {
                int c = snext();
                while (isSpaceChar(c)) {
                    c = snext();
                }
                int sgn = 1;
                if (c == '-') {
                    sgn = -1;
                    c = snext();
                }
                long res = 0;
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = snext();
                } while (!isSpaceChar(c));
                return res * sgn;
            }
    
            public int[] nextIntArray(int n) {
                int a[] = new int[n];
                for (int i = 0; i < n; i++) {
                    a[i] = nextInt();
                }
                return a;
            }
    
            public String readString() {
                int c = snext();
                while (isSpaceChar(c)) {
                    c = snext();
                }
                StringBuilder res = new StringBuilder();
                do {
                    res.appendCodePoint(c);
                    c = snext();
                } while (!isSpaceChar(c));
                return res.toString();
            }
    
            public String nextLine() {
                int c = snext();
                while (isSpaceChar(c))
                    c = snext();
                StringBuilder res = new StringBuilder();
                do {
                    res.appendCodePoint(c);
                    c = snext();
                } while (!isEndOfLine(c));
                return res.toString();
            }
    
            public boolean isSpaceChar(int c) {
                if (filter != null)
                    return filter.isSpaceChar(c);
                return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
            }
    
            private boolean isEndOfLine(int c) {
                return c == '\n' || c == '\r' || c == -1;
            }
    
            public interface SpaceCharFilter {
                public boolean isSpaceChar(int ch);
            }
        }
        class Pair{
            int le;
            int p;
            Pair(int leaves,int parent){
                le=leaves;
                p=parent;
            }
        }