sudoku

sudoku.py

#!/usr/bin/python3.7
import numpy as np
import os
import time

#grid=[ [0,0,0,2,6,0,7,0,1],[6,8,0,0,7,0,0,9,0],[1,9,0,0,0,4,5,0,0],[8,2,0,1,0,0,0,4,0],[0,0,4,6,0,2,9,0,0],[0,5,0,0,0,3,0,2,8],[0,0,9,3,0,0,0,7,4],[0,4,0,0,5,0,0,3,6],[7,0,3,0,1,8,0,0,0] ]
#grid=np.zeros((9, 9))
#World's hardest sudoku
grid=[[8,0,0,0,0,0,0,0,0],[0,3,6,0,0,0,0,0,0],[0,7,0,0,9,0,2,0,0],[0,5,0,0,0,7,0,0,0],[0,0,0,0,4,5,7,0,0],[0,0,0,1,0,0,0,3,0],[0,0,1,0,0,0,0,6,8],[0,0,8,5,0,0,0,1,0],[0,9,0,0,0,0,4,0,0]]
print(np.matrix(grid))


def possible(y,x,n):
    global grid
    for i in range(0,9):
      if grid[y][i]==n:
        return False
    for i in range(0,9):
        if grid[i][x]==n:
          return False
    x0 = (x//3)*3
    y0 = (y//3)*3
    for i in range(0,3):
        for j in range(0,3):
            if grid[y0+i][x0+j] == n:
                return False
    return True





def solve():
    start_time = time.time()
    global grid
    for y in range(9):
        for x in range(9):
            if grid[y][x]==0:
                for n in range(1,10):
                    if possible(y,x,n):
                      grid[y][x]=n
                      os.system('clear')
                      print(np.matrix(grid))
                      time.sleep(0.2)
                      solve()
                      grid[y][x]=0

                return
    print("FINISH:")
    print("--- %s seconds ---" % (time.time() - start_time))
    print(np.matrix(grid))


solve()