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.



Sample input:
3
0 1 1
1 0 1
1 1 1


Sample output:
3

Submission status: Accepted

Solution code:
import sys
MAX_INT = int(10e15)
MIN_INT = -MAX_INT
mod = 1000000007
sys.setrecursionlimit(1000000)
def IL(): return list(map(int,input().split()))
def SL(): return input().split()
def I(): return int(sys.stdin.readline())
def S(): return input()

N = I()
a = [IL() for _ in range(N)]

dp = [0]*(1 << N)
for i in range(N):
  dp[1 << i] = a[0][i]
#print(dp)

for i in range(2, N+1): # 1が立っている数
  n = (1 << i) - 1
  while n < (1 << N):
    x = n
    
    for j in range(N):
      if (x >> j) & 1:
        if a[i - 1][j] == 1:
          dp[x] += dp[x ^ (1 << j)] %mod

    """
    while x != 0:
      if x & 1 == 1:
        if a[i - 1][cnt] == 1:
          DP[n] = (DP[n] + DP[n & ~(1 << (cnt))]) % MOD
      x >>= 1
      cnt += 1
    """
    
    x = n & -n
    y = n + x
    n = ((n & ~y) // x >> 1) | y

print(dp[-1] %mod)

Submission status: Accepted

Solution code:
def popcount(x):
    c = 0
    while x > 0:
        if x & 1:
            c += 1
        x = x >> 1
    return c

def f(A):
    MOD = (10 ** 9) + 7
    n = len(A)

    dp = [0] * (1 << n)
    dp[0] = 1

    for mask in range((1 << n) - 1):
        a = popcount(mask)
        for b in range(n):
            if A[a][b] and not (mask & (1 << b)):
                m2 = mask ^ (1 << b)
                dp[m2] += dp[mask]
                if dp[m2] > MOD:
                    dp[m2] -= MOD

    return dp[(1 << n) - 1]

assert f([[0, 1, 1], [1, 0, 1], [1, 1, 1]]) == 3

n = int(input())
A = []
for _ in range(n):
    R = list(map(int, input().split()))
    A.append(R)

ans = f(A)
print(ans)

Submission status: Accepted

Solution code:
import sys
input = sys.stdin.readline

def main():
  N = int(input())
  A = [tuple(map(int,input().split())) for _ in range(N)]
  MOD =10**9+7
  N2 = 1<<N

  dp = [1] + [0 for _ in range(N2-1)]

  for i in range(N):
    nextdp = [0 for _ in range(N2)]
    for j in range(N2):
      if dp[j] != 0:
        for k in range(N):
          if (j>>k)&1 == 0 and A[i][k] == 1:
            idx = j|(1<<k)
            nextdp[idx] += dp[j]
            #nextdp[idx] %= MOD
    dp = nextdp

  print(dp[N2-1]%MOD)

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
N = int(input())

dp = [0] * (1 << N)
dp[0] = 1
curr = {0}
MOD = 10**9+7

for _ in range(N):
    a = [1 << i for i, v in enumerate(input().split()) if v == '1']
    nxt = set()
    for i in curr:
        dpi = dp[i] % MOD
        for j in a:
            if i & j:
                continue
            dp[i | j] += dpi
            nxt.add(i | j)
    curr = nxt
print(dp[(1 << N) - 1] % MOD)

Submission status: Accepted

Solution code:
#!/usr/bin/env python3
#EDPC O

import sys
import math
from bisect import bisect_right as br
from bisect import bisect_left as bl
sys.setrecursionlimit(1000000000)
from heapq import heappush, heappop,heappushpop
from collections import defaultdict
from itertools import accumulate
from collections import Counter
from collections import deque
from operator import itemgetter
from itertools import permutations
mod = 10**9 + 7
inf = float('inf')
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))

n = I()
a = [LI() for _ in range(n)]
dp = [[0]*(2**n) for _ in range(n+1)]
dp[0][0] = 1
for i in range(n):
    for j in range(2**n):
        if dp[i][j]:
            for k in range(n):
                if (j>>k)&1 == 0 and a[i][k] == 1:
                    dp[i+1][j|(1<<k)] += dp[i][j]
                    dp[i+1][j|(1<<k)] %= mod
print(dp[-1][-1])

Submission status: Accepted

Solution code:
import subprocess as sp
import sys
 
code = r"""
#include<bits/stdc++.h>
using namespace std;
const int mod=1e9+7;
int add(int x,int y){return(x+=y)<mod?x:x-mod;}
int sub(int x,int y){return(x-=y)>= 0?x:x+mod;}
int dp[1<<21];
int n,a[21][21];
int main(){
  scanf("%d",&n);
  for(int i=0;i<n;++i){
    for(int j=0;j<n;++j){
      scanf("%d",&a[i][j]);
    }
  }
  dp[0]=1;
  for(int b=1;b<(1<<n);++b){
    int bc=__builtin_popcount(b)-1;
    for(int i=0;i<n;++i){
      if((b>>i&1)&&a[bc][i]){
        dp[b]=add(dp[b],dp[b^(1<<i)]);
      }
    }
  }
  printf("%d\n",dp[(1<<n)-1]);
}
"""
 
with open("A.cpp","w") as f:
	f.write(code)
    
sp.Popen(['g++','-std=c++11','-O2',"A.cpp"]).communicate()
sp.Popen(['./a.out'],stdin=sys.stdin,stdout=sys.stdout).communicate()

Submission status: Accepted

Solution code:
mod=1000000007
#from https://ikatakos.com/pot/programming_algorithm/contest_history/atcoder/2019/0106_educational_dp_2

n=int(input())
dp=[0] * (1<<n)
dp[0]=1
curr={0}
for i in range(n):
    compatibilities=[1<<i for i,v in enumerate(input().split()) if v=="1"]
    nxt=set()
    for k in curr:
        p=dp[k]%mod
        for c in compatibilities:
            if k&c: continue
            dp[k|c]+=p
            nxt.add(k|c)
    curr=nxt

print(dp[(1<<n)-1]%mod)

Submission status: Accepted

Solution code:
import numpy as np

MOD = 10 ** 9 + 7
N=int(input())
A = [[int(x) for x in input().split()] for _ in range(N)]

dp = np.zeros(1<<N, dtype=np.uint64)
dp[0] = 1

for A_row in A:
    prev = dp.copy()
    dp = np.zeros_like(prev)
    for n,a in enumerate(A_row):
        if not a:
            continue
        x = 1 << n
        dp[x:] += prev[:-x]
    dp %= MOD

answer = dp[-1]
print(answer)

Submission status: Accepted

Solution code:
#!usr/bin/env python3
from collections import defaultdict
from collections import deque
from heapq import heappush, heappop
import sys
import math
import bisect
import random
def LI(): return list(map(int, sys.stdin.readline().split()))
def I(): return int(sys.stdin.readline())
def LS():return list(map(list, sys.stdin.readline().split()))
def S(): return list(sys.stdin.readline())[:-1]
def IR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = I()
    return l
def LIR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = LI()
    return l
def SR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = S()
    return l
def LSR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = SR()
    return l
sys.setrecursionlimit(1000000)
mod = 1000000007


#A
def A():
    n,k = LI()
    a = LI()
    dp = [0 for i in range(k+1)]
    f = [0 for i in range(k+1)]
    for i in range(k+1):
        if not f[i]:
            for j in a:
                if i-j >= 0:
                    dp[i] = 1-dp[i-j]
                    if dp[i] == 0:
                        break
            else:
                dp[i] = 1
    print(["First","Second"][dp[k]])
#B
def B():
    n = I()
    a = LI()
    ma = n*(n+1)//2
    su = sum(a)
    s = [1 for i in range(n+1)]
    for i in range(1,n):
        s[i+1] = s[i]+n-i+1
    d = [None for i in range(ma+1)]
    d[0] = 0
    k = 1
    for i in range(1,n+1):
        for j in range(n+1-i):
            d[k+j] = i
        k += n+1-i
    k = n%2
    dp = [su if (d[i]+k)%2 else -su for i in range(ma+1)]
    dp[0] = 0
    if k:
        for i in range(n):
            dp[i+1] = a[n-1-i]
    else:
        for i in range(n):
            dp[i+1] = -a[n-1-i]
    for i in range(1,ma):
        r = n-1-(i-s[d[i]])
        l = r+1-d[i]
        j = i+(n-d[i])
        j2 = j+1
        if (d[i]+k)%2:
            if r < n-1:
                if a[r+1]+dp[i] > dp[j]:
                    dp[j] = a[r+1]+dp[i]
            if l > 0:
                if a[l-1]+dp[i] > dp[j2]:
                    dp[j2] = a[l-1]+dp[i]
        else:
            if r < n-1:
                if -a[r+1]+dp[i] < dp[j]:
                    dp[j] = -a[r+1]+dp[i]
            if l > 0:
                if -a[l-1]+dp[i] < dp[j2]:
                    dp[j2] = -a[l-1]+dp[i]
    print(dp[ma])
    return

#C
def C():
    def comb(a,b):
        return fact[a]*inv[b]*inv[a-b]%mod

    n,k = LI()
    a = LI()
    """
    fact = [1]
    for i in range(n+k):
        fact.append(fact[-1]*(i+1)%mod)
    inv = [1]*(n+k+1)
    inv[n+k] = pow(fact[n+k],mod-2,mod)
    for i in range(n+k)[::-1]:
        inv[i] = inv[i+1]*(i+1)%mod
    f = [comb(i+n-1,n-1) for i in range(k+1)]
    for i in a:
        for j in range(k-i)[::-1]:
            f[j+i+1] -= f[j]
            f[j+i+1] %= mod
    print(f[k])
    """
    dp = [[0]*(k+1) for i in range(n+1)]
    for i in range(k+1):
        dp[0][i] = 1
    for i in range(n):
        ni = i+1
        ai = a[i]
        for j in range(k+1):
            if j >= ai+1:
                dp[ni][j] = (dp[i][j]-dp[i][j-ai-1])%mod
            else:
                dp[ni][j] = dp[i][j]
        if i < n-1:
            for j in range(k):
                dp[ni][j+1] += dp[ni][j]
                dp[ni][j+1] %= mod
    print(dp[n][k]%mod)
    return

#D
def D():
    n = I()
    a = LI()
    a.insert(0,0)
    for i in range(n):
        a[i+1] += a[i]
    dp = [[0]*(n+1) for i in range(n)]
    for le in range(1,n):
        for l in range(n-le):
            r = l+le+1
            res = float("inf")
            for i in range(l+1,r):
                m = dp[l][i]+dp[i][r]
                if m < res:
                    res = m
            res += a[r]-a[l]
            dp[l][r] = res
    print(dp[0][n])
    return

#E
def E():

    n = I()
    a = LIR(n)
    m = 1<<n
    dp = [0]*m
    dp[0] = 1
    a = [[j for j in range(n) if a[i][j]] for i in range(n)]
    bit_count = [-1]
    for i in range(n):
        for j in range(len(bit_count)):
            bit_count.append(bit_count[j]+1)
    for k in range(1,m):
        i = bit_count[k]
        for j in a[i]:
            bj = 1<<j
            if bj > k:
                break
            if not k&bj:
                continue
            nk = k^bj
            dp[k] += dp[nk]
    print(dp[m-1]%mod)
#F
def F():
    return

#G
def G():
    return

#H
def H():
    return

#Solve
if __name__ == "__main__":
    E()

Submission status: Accepted

Solution code:
#!usr/bin/env python3
from collections import defaultdict
from collections import deque
from heapq import heappush, heappop
import sys
import math
import bisect
import random
def LI(): return list(map(int, sys.stdin.readline().split()))
def I(): return int(sys.stdin.readline())
def LS():return list(map(list, sys.stdin.readline().split()))
def S(): return list(sys.stdin.readline())[:-1]
def IR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = I()
    return l
def LIR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = LI()
    return l
def SR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = S()
    return l
def LSR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = SR()
    return l
sys.setrecursionlimit(1000000)
mod = 1000000007


#A
def A():
    n,k = LI()
    a = LI()
    dp = [0 for i in range(k+1)]
    f = [0 for i in range(k+1)]
    for i in range(k+1):
        if not f[i]:
            for j in a:
                if i-j >= 0:
                    dp[i] = 1-dp[i-j]
                    if dp[i] == 0:
                        break
            else:
                dp[i] = 1
    print(["First","Second"][dp[k]])
#B
def B():
    n = I()
    a = LI()
    ma = n*(n+1)//2
    su = sum(a)
    s = [1 for i in range(n+1)]
    for i in range(1,n):
        s[i+1] = s[i]+n-i+1
    d = [None for i in range(ma+1)]
    d[0] = 0
    k = 1
    for i in range(1,n+1):
        for j in range(n+1-i):
            d[k+j] = i
        k += n+1-i
    k = n%2
    dp = [su if (d[i]+k)%2 else -su for i in range(ma+1)]
    dp[0] = 0
    if k:
        for i in range(n):
            dp[i+1] = a[n-1-i]
    else:
        for i in range(n):
            dp[i+1] = -a[n-1-i]
    for i in range(1,ma):
        r = n-1-(i-s[d[i]])
        l = r+1-d[i]
        j = i+(n-d[i])
        j2 = j+1
        if (d[i]+k)%2:
            if r < n-1:
                if a[r+1]+dp[i] > dp[j]:
                    dp[j] = a[r+1]+dp[i]
            if l > 0:
                if a[l-1]+dp[i] > dp[j2]:
                    dp[j2] = a[l-1]+dp[i]
        else:
            if r < n-1:
                if -a[r+1]+dp[i] < dp[j]:
                    dp[j] = -a[r+1]+dp[i]
            if l > 0:
                if -a[l-1]+dp[i] < dp[j2]:
                    dp[j2] = -a[l-1]+dp[i]
    print(dp[ma])
    return

#C
def C():
    def comb(a,b):
        return fact[a]*inv[b]*inv[a-b]%mod

    n,k = LI()
    a = LI()
    """
    fact = [1]
    for i in range(n+k):
        fact.append(fact[-1]*(i+1)%mod)
    inv = [1]*(n+k+1)
    inv[n+k] = pow(fact[n+k],mod-2,mod)
    for i in range(n+k)[::-1]:
        inv[i] = inv[i+1]*(i+1)%mod
    f = [comb(i+n-1,n-1) for i in range(k+1)]
    for i in a:
        for j in range(k-i)[::-1]:
            f[j+i+1] -= f[j]
            f[j+i+1] %= mod
    print(f[k])
    """
    dp = [[0]*(k+1) for i in range(n+1)]
    for i in range(k+1):
        dp[0][i] = 1
    for i in range(n):
        ni = i+1
        ai = a[i]
        for j in range(k+1):
            if j >= ai+1:
                dp[ni][j] = (dp[i][j]-dp[i][j-ai-1])%mod
            else:
                dp[ni][j] = dp[i][j]
        if i < n-1:
            for j in range(k):
                dp[ni][j+1] += dp[ni][j]
                dp[ni][j+1] %= mod
    print(dp[n][k]%mod)
    return

#D
def D():
    n = I()
    a = LI()
    a.insert(0,0)
    for i in range(n):
        a[i+1] += a[i]
    dp = [[0]*(n+1) for i in range(n)]
    for le in range(1,n):
        for l in range(n-le):
            r = l+le+1
            res = float("inf")
            for i in range(l+1,r):
                m = dp[l][i]+dp[i][r]
                if m < res:
                    res = m
            res += a[r]-a[l]
            dp[l][r] = res
    print(dp[0][n])
    return

#E
def E():

    n = I()
    a = LIR(n)
    m = 1<<n
    dp = [0]*m
    dp[0] = 1
    a = [[j for j in range(n) if a[i][j]] for i in range(n)]
    bit_count = [0]
    for i in range(n):
        for j in range(len(bit_count)):
            bit_count.append(bit_count[j]+1)
    for k in range(1,m):
        i = bit_count[k]-1
        for j in a[i]:
            bj = 1<<j
            if bj > k:
                break
            if not k&bj:
                continue
            nk = k^bj
            dp[k] += dp[nk]
    print(dp[m-1]%mod)
#F
def F():
    return

#G
def G():
    return

#H
def H():
    return

#Solve
if __name__ == "__main__":
    E()

Submission status: Accepted

Solution code:
#!usr/bin/env python3
from collections import defaultdict
from collections import deque
from heapq import heappush, heappop
import sys
import math
import bisect
import random
def LI(): return list(map(int, sys.stdin.readline().split()))
def I(): return int(sys.stdin.readline())
def LS():return list(map(list, sys.stdin.readline().split()))
def S(): return list(sys.stdin.readline())[:-1]
def IR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = I()
    return l
def LIR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = LI()
    return l
def SR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = S()
    return l
def LSR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = SR()
    return l
sys.setrecursionlimit(1000000)
mod = 1000000007


#A
def A():
    n,k = LI()
    a = LI()
    dp = [0 for i in range(k+1)]
    f = [0 for i in range(k+1)]
    for i in range(k+1):
        if not f[i]:
            for j in a:
                if i-j >= 0:
                    dp[i] = 1-dp[i-j]
                    if dp[i] == 0:
                        break
            else:
                dp[i] = 1
    print(["First","Second"][dp[k]])
#B
def B():
    n = I()
    a = LI()
    ma = n*(n+1)//2
    su = sum(a)
    s = [1 for i in range(n+1)]
    for i in range(1,n):
        s[i+1] = s[i]+n-i+1
    d = [None for i in range(ma+1)]
    d[0] = 0
    k = 1
    for i in range(1,n+1):
        for j in range(n+1-i):
            d[k+j] = i
        k += n+1-i
    k = n%2
    dp = [su if (d[i]+k)%2 else -su for i in range(ma+1)]
    dp[0] = 0
    if k:
        for i in range(n):
            dp[i+1] = a[n-1-i]
    else:
        for i in range(n):
            dp[i+1] = -a[n-1-i]
    for i in range(1,ma):
        r = n-1-(i-s[d[i]])
        l = r+1-d[i]
        j = i+(n-d[i])
        j2 = j+1
        if (d[i]+k)%2:
            if r < n-1:
                if a[r+1]+dp[i] > dp[j]:
                    dp[j] = a[r+1]+dp[i]
            if l > 0:
                if a[l-1]+dp[i] > dp[j2]:
                    dp[j2] = a[l-1]+dp[i]
        else:
            if r < n-1:
                if -a[r+1]+dp[i] < dp[j]:
                    dp[j] = -a[r+1]+dp[i]
            if l > 0:
                if -a[l-1]+dp[i] < dp[j2]:
                    dp[j2] = -a[l-1]+dp[i]
    print(dp[ma])
    return

#C
def C():
    def comb(a,b):
        return fact[a]*inv[b]*inv[a-b]%mod

    n,k = LI()
    a = LI()
    """
    fact = [1]
    for i in range(n+k):
        fact.append(fact[-1]*(i+1)%mod)
    inv = [1]*(n+k+1)
    inv[n+k] = pow(fact[n+k],mod-2,mod)
    for i in range(n+k)[::-1]:
        inv[i] = inv[i+1]*(i+1)%mod
    f = [comb(i+n-1,n-1) for i in range(k+1)]
    for i in a:
        for j in range(k-i)[::-1]:
            f[j+i+1] -= f[j]
            f[j+i+1] %= mod
    print(f[k])
    """
    dp = [[0]*(k+1) for i in range(n+1)]
    for i in range(k+1):
        dp[0][i] = 1
    for i in range(n):
        ni = i+1
        ai = a[i]
        for j in range(k+1):
            if j >= ai+1:
                dp[ni][j] = (dp[i][j]-dp[i][j-ai-1])%mod
            else:
                dp[ni][j] = dp[i][j]
        if i < n-1:
            for j in range(k):
                dp[ni][j+1] += dp[ni][j]
                dp[ni][j+1] %= mod
    print(dp[n][k]%mod)
    return

#D
def D():
    n = I()
    a = LI()
    a.insert(0,0)
    for i in range(n):
        a[i+1] += a[i]
    dp = [[0]*(n+1) for i in range(n)]
    for le in range(1,n):
        for l in range(n-le):
            r = l+le+1
            res = float("inf")
            for i in range(l+1,r):
                m = dp[l][i]+dp[i][r]
                if m < res:
                    res = m
            res += a[r]-a[l]
            dp[l][r] = res
    print(dp[0][n])
    return

#E
def E():

    n = I()
    a = LIR(n)
    m = 1<<n
    dp = [0]*m
    dp[0] = 1
    a = [[j for j in range(n) if a[i][j]] for i in range(n)]
    bit_count = [0]
    for i in range(n):
        for j in range(len(bit_count)):
            bit_count.append(bit_count[j]+1)
    for k in range(1,m):
        i = bit_count[k]-1
        for j in a[i]:
            bj = 1<<j
            if bj > k:
                break
            if not k&bj:
                continue
            nk = k^bj
            dp[k] += dp[nk]
            dp[k] %= mod
    print(dp[m-1])
#F
def F():
    return

#G
def G():
    return

#H
def H():
    return

#Solve
if __name__ == "__main__":
    E()

Submission status: Accepted

Solution code:
#!usr/bin/env python3
from collections import defaultdict
from collections import deque
from heapq import heappush, heappop
import sys
import math
import bisect
import random
def LI(): return list(map(int, sys.stdin.readline().split()))
def I(): return int(sys.stdin.readline())
def LS():return list(map(list, sys.stdin.readline().split()))
def S(): return list(sys.stdin.readline())[:-1]
def IR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = I()
    return l
def LIR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = LI()
    return l
def SR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = S()
    return l
def LSR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = SR()
    return l
sys.setrecursionlimit(1000000)
mod = 1000000007


#A
def A():
    n,k = LI()
    a = LI()
    dp = [0 for i in range(k+1)]
    f = [0 for i in range(k+1)]
    for i in range(k+1):
        if not f[i]:
            for j in a:
                if i-j >= 0:
                    dp[i] = 1-dp[i-j]
                    if dp[i] == 0:
                        break
            else:
                dp[i] = 1
    print(["First","Second"][dp[k]])
#B
def B():
    n = I()
    a = LI()
    ma = n*(n+1)//2
    su = sum(a)
    s = [1 for i in range(n+1)]
    for i in range(1,n):
        s[i+1] = s[i]+n-i+1
    d = [None for i in range(ma+1)]
    d[0] = 0
    k = 1
    for i in range(1,n+1):
        for j in range(n+1-i):
            d[k+j] = i
        k += n+1-i
    k = n%2
    dp = [su if (d[i]+k)%2 else -su for i in range(ma+1)]
    dp[0] = 0
    if k:
        for i in range(n):
            dp[i+1] = a[n-1-i]
    else:
        for i in range(n):
            dp[i+1] = -a[n-1-i]
    for i in range(1,ma):
        r = n-1-(i-s[d[i]])
        l = r+1-d[i]
        j = i+(n-d[i])
        j2 = j+1
        if (d[i]+k)%2:
            if r < n-1:
                if a[r+1]+dp[i] > dp[j]:
                    dp[j] = a[r+1]+dp[i]
            if l > 0:
                if a[l-1]+dp[i] > dp[j2]:
                    dp[j2] = a[l-1]+dp[i]
        else:
            if r < n-1:
                if -a[r+1]+dp[i] < dp[j]:
                    dp[j] = -a[r+1]+dp[i]
            if l > 0:
                if -a[l-1]+dp[i] < dp[j2]:
                    dp[j2] = -a[l-1]+dp[i]
    print(dp[ma])
    return

#C
def C():
    def comb(a,b):
        return fact[a]*inv[b]*inv[a-b]%mod

    n,k = LI()
    a = LI()
    """
    fact = [1]
    for i in range(n+k):
        fact.append(fact[-1]*(i+1)%mod)
    inv = [1]*(n+k+1)
    inv[n+k] = pow(fact[n+k],mod-2,mod)
    for i in range(n+k)[::-1]:
        inv[i] = inv[i+1]*(i+1)%mod
    f = [comb(i+n-1,n-1) for i in range(k+1)]
    for i in a:
        for j in range(k-i)[::-1]:
            f[j+i+1] -= f[j]
            f[j+i+1] %= mod
    print(f[k])
    """
    dp = [[0]*(k+1) for i in range(n+1)]
    for i in range(k+1):
        dp[0][i] = 1
    for i in range(n):
        ni = i+1
        ai = a[i]
        for j in range(k+1):
            if j >= ai+1:
                dp[ni][j] = (dp[i][j]-dp[i][j-ai-1])%mod
            else:
                dp[ni][j] = dp[i][j]
        if i < n-1:
            for j in range(k):
                dp[ni][j+1] += dp[ni][j]
                dp[ni][j+1] %= mod
    print(dp[n][k]%mod)
    return

#D
def D():
    n = I()
    a = LI()
    a.insert(0,0)
    for i in range(n):
        a[i+1] += a[i]
    dp = [[0]*(n+1) for i in range(n)]
    for le in range(1,n):
        for l in range(n-le):
            r = l+le+1
            res = float("inf")
            for i in range(l+1,r):
                m = dp[l][i]+dp[i][r]
                if m < res:
                    res = m
            res += a[r]-a[l]
            dp[l][r] = res
    print(dp[0][n])
    return

#E
def E():
    def bit_count(n):
        return bin(n).count("1")

    n = I()
    a = LIR(n)
    m = 1<<n
    dp = [0]*m
    dp[0] = 1
    a = [[j for j in range(n) if a[i][j]] for i in range(n)]
    for k in range(1,m):
        i = bit_count(k)-1
        for j in a[i]:
            bj = 1<<j
            if bj > k:
                break
            if not k&bj:
                continue
            nk = k^bj
            dp[k] += dp[nk]
            dp[k] %= mod
    print(dp[m-1])
#F
def F():
    return

#G
def G():
    return

#H
def H():
    return

#Solve
if __name__ == "__main__":
    E()

Submission status: Accepted

Solution code:
from numpy import*
M=10**9+7
n,*a=open(0)
n=int(n)
d=zeros(2**n,'u8')
d[0]=1
for a in a:
  b,d=d,zeros(2**n,'u8')
  for i,a in enumerate(map(int,a.split())):
    if a:
      j=2**i
      d[j:]+=b[:-j]
  d%=M
print(d[-1])

Submission status: Accepted

Solution code:
def main():
  M=10**9+7
  n,*a=open(0)
  n=int(n)
  a=[list(map(int,t[::2]))for t in a]
  dp=[1]+[0]*(2**n-1)
  for i in range(2**n-1):
    j=bin(i).count('1')
    for k in range(n):
      to=i|1<<k
      if to==i or not a[j][k]:continue
      dp[to]+=dp[i]
      dp[to]%=M
  print(dp[-1])
main()

Submission status: Accepted

Solution code:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)

MOD = 10 ** 9 + 7
N = int(input())
A = [[int(x) for x in input().split()] for _ in range(N)]

bit_count = [0]
for _ in range(N):
    bit_count += [x+1 for x in bit_count]
    
dp = [0] * (1<<N)
dp[0] = 1

for i in range((1<<N)-1):
    k = bit_count[i]
    for c in range(N):
        if A[k][c]:
            dp[(1<<c)^i] += dp[i]

answer = dp[-1] % MOD
print(answer)

Submission status: Accepted

Solution code:
# @author 

import sys

class OMatching:
    def solve(self):
        from collections import defaultdict

        def numberOfSetBits(i):
            i = i - ((i >> 1) & 0x55555555)
            i = (i & 0x33333333) + ((i >> 2) & 0x33333333)
            return (((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) & 0xffffffff) >> 24

        MOD = 10 ** 9 + 7

        n = int(input())
        a = []
        for i in range(n):
            a.append([int(_) for _ in input().split()])


        dp = [[0] * ((1 << n) + 1) for _ in range(n + 1)]
        dp[0][0] = 1
        by_1 = defaultdict(list)
        for j in range(1 << n):
            by_1[numberOfSetBits(j)].append(j)
        # for j in range(1 << n):
        #     by_1[bin(j).count('1')].append(j)

        for i in range(1, n + 1):
            for j in by_1[i - 1]:
                for k in range(n):
                    if (j >> k) & 1 or a[i - 1][k] == 0:
                        continue
                    dp[i][j | (1 << k)] += dp[i - 1][j]
                    dp[i][j | (1 << k)] %= MOD

        # [print(item) for item in dp]

        print(sum(dp[n]))

solver = OMatching()
input = sys.stdin.readline

solver.solve()

Submission status: Accepted

Solution code:
N = int(input())
a = [list(map(int, input().split())) for i in range(N)]
MOD = 10 ** 9 + 7
M = pow(2, N)

DP = [0] * M
for i in range(N):
  DP[1 << i] = a[0][i]

for i in range(2, N + 1):
  n = (1 << i) - 1
  while n < (1 << N):
    x = n
    cnt = 0
    while x != 0:
      if x & 1 == 1:
        if a[i - 1][cnt] == 1:
          DP[n] = (DP[n] + DP[n & ~(1 << (cnt))]) % MOD
      x >>= 1
      cnt += 1

    x = n & -n
    y = n + x
    n = ((n & ~y) // x >> 1) | y

print(DP[-1])

Submission status: Accepted

Solution code:
import sys
input = sys.stdin.readline
'''
allinputs = iter(input().splitlines())
input = lambda : next(allinputs)
#'''
N = int(input())
a = [list(map(int, input().split())) for _ in range(N)]
mod = 10 ** 9 + 7
dp = [0] * (1 << N)
#dp[n] = c: 考慮する女の組を二進数で表す。iを考慮する女の数とすると、考慮する男は先頭からi番目まで。c: そのときの組み合わせ数。
dp[0] = 1
def bitcount(i): # i < 2^32
    i = i - ((i >> 1) & 0x55555555)
    i = (i & 0x33333333) + ((i >> 2) & 0x33333333)
    return (((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) & 0xffffffff) >> 24
	
	
for n in range(1 << N):
	i = bitcount(n)
	c = dp[n]
	tmp = n
	tmp ^= (1 << N) - 1
	for j in range(N):
		r = 1 & tmp
		if r == 1 and a[i - 1][j] == 1:
			nc = dp[n + (1 << j)] + c 
			if nc >= mod:
				nc -= mod
			
			dp[n + (1 << j)] = nc
			
		tmp = tmp >> 1
		if tmp == 0:
			break
				
print(dp[-1])

Submission status: Accepted

Solution code:
# coding: utf-8
# Your code here!
n=int(input())
A= [[int(i) for i in input().split()] for j in range(n)]

def bitcount(i): # i < 2^32
    i = i - ((i >> 1) & 0x55555555)
    i = (i & 0x33333333) + ((i >> 2) & 0x33333333)
    return (((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) & 0xffffffff) >> 24
    

MOD=10**9+7
size=1<<n
dp = [0]*size
dp[0] = 1

for i in range(size-1):
#    num = bin(i).count("1")
    num = bitcount(i)
    for c in range(n):
        if A[num][c] and (1<<c)^i != i:
            dp[(1<<c)^i] += dp[i]
            if dp[(1<<c)^i] > MOD: dp[(1<<c)^i] -= MOD

print(dp[-1])

Submission status: Accepted

Solution code:
n=int(input())
A= [[int(i) for i in input().split()] for j in range(n)]

MOD=10**9+7
size=1<<n
dp = [0]*size
dp[0] = 1
for i in range(size-1):
    num = bin(i).count("1")
    for c in range(n):
        new = (1<<c)^i
        if A[num][c] and new != i:
            dp[new] += dp[i]
            if dp[new] > MOD: dp[new] -= MOD

print(dp[-1])

Submission status: Accepted

Solution code:
import itertools
import fileinput
 
 
def solve_match(match_matrix):
    size = len(match_matrix)

    combo_list = [0] * (2**size)

    combo_indexes = [[] for _ in range(size + 1)]
    for i in range(2**size):
        count = 0
        n = i
        while (n): 
            count += n & 1
            n >>= 1
        combo_indexes[count].append(i)

    for col in range(size):
        for combo in combo_indexes[col + 1]:
            if col == 0:
                for i in range(size):
                    if (combo & (1 << i)):
                        combo_list[combo] = match_matrix[i][col]
                        break
            else:
                s = 0
                cnt = 0
                for i in range(size):
                    flag = 1 << i
                    if (combo & flag) and match_matrix[i][col] == 1:
                        s += combo_list[combo & (~flag)]
                        cnt += 1
                        if cnt == col + 1:
                            break
                
                combo_list[combo] = s % (10**9 + 7)
    return combo_list[-1]
 
 
inp = fileinput.FileInput()
n = int(inp.readline())
 
arr = []
for _ in range(n):
    arr.append([int(v) for v in inp.readline().split(" ")])
 
print(solve_match(arr))

Submission status: Accepted

Solution code:
def calcdp(i, s):
    # i番目の男性まで評価しときに、女性のマッチング状態がsとなる組み合わせの数
    global dp, MOD, N, A
    if dp[i][s] != -1:
        return dp[i][s]
    
    r = 0
    for j in range(N):
        if A[i-1][j] and s & (1 << j):
            r += calcdp(i - 1, s ^ (1 << j))
    
    dp[i][s] = r = r % MOD
    return r


N = int(input())
A = [[int(x) for x in input().split()] for _ in range(N)]
MOD = 10**9 + 7

dp = [[-1] * 2**N for _ in range(N+1)]
dp[0][0] = 1

print(calcdp(N, 2**N-1))