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Sudoku_solver.py
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Sudoku_solver.py
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import numpy as np
import time
import copy
class MeasureTime:
def __init__(self,tag="It"):
self.tag=tag
def __enter__(self):
self.t0=time.time()
def __exit__(self,type,value,traceback):
print(f"\n{self.tag} took {time.time()-self.t0} s.\n")
def read_puzzle(text,n=9):
return np.array([int(num) for num in text],dtype=int).reshape((n,n))
def get_block_inds(rowind,colind,m):
return rowind//m*m+colind//m
def baby_sudoku(puzzle0,n=3):
numset={*range(1,n+1)}
row_opts=[set()]*n
col_opts=[set()]*n
for ind in range(n):
row=puzzle0[ind,:]
col=puzzle0[:,ind]
if len(row[row>0])!=len(set(row[row>0])) or len(col[col>0])!=len(set(col[col>0])):
return False,None
def _solve(puzzle):
zero_inds=list(zip(*np.where(puzzle==0)))
if not zero_inds:
return True,puzzle
for ind in range(n):
row_opts[ind]=numset.difference(puzzle[ind,:])
col_opts[ind]=numset.difference(puzzle[:,ind])
for (rowind,colind) in zero_inds:
options=row_opts[rowind].intersection(col_opts[colind])
if not options:
return False,None
for num in options:
#print("bf",rowind,colind,num)
puzzle[rowind,colind]=num
success,result=_solve(puzzle)
#print("af",rowind,colind,num,success)
if success:
return True,puzzle
return False,None
def sudoku(puzzle0,n=9):
numset={*range(1,n+1)}
row_opts=[set()]*n
col_opts=[set()]*n
m=int(np.sqrt(n))
block_opts=[set()]*n
blockinds=np.array([[get_block_inds(i,j,m) for j in range(n)] for i in range(n)])
#print("puzzle:",puzzle0)#;#input()
for ind in range(n):
row=puzzle0[ind,:]
col=puzzle0[:,ind]
if len(row[row>0])!=len(set(row[row>0])) or len(col[col>0])!=len(set(col[col>0])):
#print("Spatne zadane")
return False,None
zero_inds=list(zip(*np.where(puzzle0==0)))
def _solve(puzzle,zer_num=0):
if zer_num>=len(zero_inds):
return True,puzzle
for ind in range(n):
row_opts[ind]=numset.difference(puzzle[ind,:])
col_opts[ind]=numset.difference(puzzle[:,ind])
block_row=ind//m
block_col=ind%m
block_opts[ind]=numset.difference(puzzle[block_row*m:(block_row+1)*m,block_col*m:(block_col+1)*m].reshape(m*m))
(rowind,colind)=zero_inds[zer_num]
options=row_opts[rowind].intersection(col_opts[colind]).intersection(block_opts[blockinds[rowind,colind]])
if len(zero_inds)==1 and len(options)>1:
raise ValueError("Non-unique!")
if not options:
#print(f"No options!({rowind+1},{colind+1})\n",puzzle)
#input()
return False,None
for num in options:
#print(f"In ({rowind+1},{colind+1}),options: {options},trying: {num}")
puzzle[rowind,colind]=num
#print(puzzle);#input()
success,result=_solve(np.array(puzzle),zer_num+1)
if success:
return True,result
#print(f"In ({rowind+1},{colind+1}),options: {options},failed: {num}")
#input()
return False,None
return _solve(puzzle0)
def sudoku2(puzzle0,n=9):
global failed_count
numset={*range(1,n+1)}
row_opts=[set()]*n
col_opts=[set()]*n
m=int(np.sqrt(n))
block_opts=[set()]*n
blockinds=np.array([[get_block_inds(i,j,m) for j in range(n)] for i in range(n)])
failed_count=0
#print("puzzle:",puzzle0)#;#input()
for ind in range(n):
row=puzzle0[ind,:]
col=puzzle0[:,ind]
if len(row[row>0])!=len(set(row[row>0])) or len(col[col>0])!=len(set(col[col>0])):
#print("Spatne zadane")
return False,None
for ind in range(n):
row_opts[ind]=numset.difference(puzzle[ind,:])
col_opts[ind]=numset.difference(puzzle[:,ind])
block_row=ind//m
block_col=ind%m
block_opts[ind]=numset.difference(puzzle[block_row*m:(block_row+1)*m,block_col*m:(block_col+1)*m].reshape(m*m))
zero_inds=sorted(zip(*np.where(puzzle0==0)),key=lambda inds: (row_opts[inds[0]].intersection(col_opts[inds[1]]).intersection(block_opts[blockinds[inds[0],inds[1]]])))
def _solve(puzzle,zer_num=0):
global failed_count
if zer_num>=len(zero_inds):
return True,puzzle
for ind in range(n):
row_opts[ind]=numset.difference(puzzle[ind,:])
col_opts[ind]=numset.difference(puzzle[:,ind])
block_row=ind//m
block_col=ind%m
block_opts[ind]=numset.difference(puzzle[block_row*m:(block_row+1)*m,block_col*m:(block_col+1)*m].reshape(m*m))
(rowind,colind)=zero_inds[zer_num]
options=row_opts[rowind].intersection(col_opts[colind]).intersection(block_opts[blockinds[rowind,colind]])
#if len(zero_inds)==1 and len(options)>1:
# raise ValueError("Non-unique!")
if not options:
#print(f"No options!({rowind+1},{colind+1})\n",puzzle)
#input()
failed_count+=1
return False,None
for num in options:
#print(f"In ({rowind+1},{colind+1}),options: {options},trying: {num}")
puzzle[rowind,colind]=num
#print(puzzle);#input()
success,result=_solve(np.array(puzzle),zer_num+1)
if success:
return True,result
#print(f"In ({rowind+1},{colind+1}),options: {options},failed: {num}")
#input()
return False,None
sol=_solve(np.array(puzzle0))
print("Number of attempts: ",failed_count+1)
return sol
def sudoku3(puzzle0,n=9):
global failed_count
numset={*range(1,n+1)}
row_opts=[set()]*n
col_opts=[set()]*n
m=int(np.sqrt(n))
block_opts=[set()]*n
blockinds=np.array([[get_block_inds(i,j,m) for j in range(n)] for i in range(n)])
failed_count=0
#print("puzzle:",puzzle0)#;#input()
for ind in range(n):
row=puzzle0[ind,:]
col=puzzle0[:,ind]
if len(row[row>0])!=len(set(row[row>0])) or len(col[col>0])!=len(set(col[col>0])):
#print("Spatne zadane")
return False,None
for ind in range(n):
row_opts[ind]=numset.difference(puzzle[ind,:])
col_opts[ind]=numset.difference(puzzle[:,ind])
block_row=ind//m
block_col=ind%m
block_opts[ind]=numset.difference(puzzle[block_row*m:(block_row+1)*m,block_col*m:(block_col+1)*m].reshape(m*m))
zero_inds=list(zip(*np.where(puzzle0==0)))
zero_inds=[(zero_ind[0],zero_ind[1],blockinds[zero_ind[0],zero_ind[1]]) for zero_ind in zero_inds]
print(zero_inds)
ind_queue=[[zero_ind,len(row_opts[zero_ind[0]].intersection(col_opts[zero_ind[1]]).intersection(block_opts[zero_ind[2]]))] for zero_ind in zero_inds]
ind_queue=sorted(ind_queue,key=lambda x: x[1])
def _solve(puzzle,ind_queue,row_opts,col_opts,block_opts,zer_num=0):
global failed_count
if zer_num>=len(zero_inds):
return True,puzzle
(rowind,colind,blockind)=ind_queue[0][0]
options=row_opts[rowind].intersection(col_opts[colind]).intersection(block_opts[blockind])
#if len(zero_inds)==1 and len(options)>1:
# raise ValueError("Non-unique!")
if not options:
#print(f"No options!({rowind+1},{colind+1})\n",puzzle)
#input()
failed_count+=1
return False,None
for num in options:
#print(f"In ({rowind+1},{colind+1}),options: {options},trying: {num}")
puzzle[rowind,colind]=num
#print(puzzle);#input()
new_queue=copy.deepcopy(ind_queue[1:])
nrow_opts=copy.deepcopy(row_opts)
ncol_opts=copy.deepcopy(col_opts)
nblock_opts=copy.deepcopy(block_opts)
nrow_opts[rowind].remove(num)
ncol_opts[colind].remove(num)
nblock_opts[blockind].remove(num)
for ind,((rowind2,colind2,blockind2),_) in enumerate(new_queue):
if rowind2==rowind or colind2==colind or blockind2==blockind:
new_queue[ind][1]-=1
new_queue=sorted(new_queue,key=lambda x: x[1])
success,result=_solve(np.array(puzzle),new_queue,nrow_opts,ncol_opts,nblock_opts,zer_num+1)
if success:
return True,result
#print(f"In ({rowind+1},{colind+1}),options: {options},failed: {num}")
#input()
return False,None
sol=_solve(np.array(puzzle0),ind_queue,row_opts,col_opts,block_opts)
print("Number of attempts: ",failed_count+1)
return sol
#puzzle=read_puzzle("004006079000000602056092300078061030509000406020540890007410920105000000840600100",n=9)
#puzzle=read_puzzle("196305482427018356053204079612740835948501000075082041500026790789150260064897510",n=9)
#puzzle=read_puzzle("400000805030000000000700000020000060000080400000010000000603070500200000104000000",n=9)
puzzle=read_puzzle("020503001050000349070190056000000700730200508005074130008309000302006900197052603",n=9)
#puzzle=read_puzzle("070000043040009610800634900094052000358460020000800530080070091902100005007040802",n=9)
#puzzle=read_puzzle("004300209005009001070060043006002087190007400050083000600000105003508690042910300",n=9)
#s="078010609203009008410060052720106030000400700091305000932000400005720010000008006"
#puzzle=read_puzzle(s,n=9)
#puzzle0=read_puzzle("231002023",n=3)
#def solve_sudoku(puzzle):
# def _solve()
##print(baby_sudoku(puzzle0,n=3))
with MeasureTime("Solving the sudoku"):
solvable,solution=sudoku2(puzzle,n=9)
n=9
from colorama import Fore,Style
if solvable:
print("\n{:^30}".format("Puzzle:")+"\t\t\t"+"{:^35}".format("Solution:")+"\n")
for row in range(n//2):
for col_sep in range(n//3):
print(f"{Fore.RED}|{Fore.BLACK} "+" | ".join((str(num) if num>0 else " " for num in puzzle[row,col_sep*n//3:(col_sep+1)*n//3])),end="")
print(f"{Fore.RED} |{Fore.BLACK}",end="")
print("\t\t",end="")
for col_sep in range(n//3):
print(f"{Fore.RED}|{Fore.BLACK} "+" | ".join((str(num) if num>0 else " " for num in solution[row,col_sep*n//3:(col_sep+1)*n//3])),end="")
print(f"{Fore.RED} |{Fore.BLACK}")
if (row+1)%3==0:
print(" "*(n)+"\t\t"+" "*(n))
for col_sep in range(n//3):
print(f"{Fore.RED}|{Fore.BLACK} "+" | ".join((str(num) if num>0 else " " for num in puzzle[n//2,col_sep*n//3:(col_sep+1)*n//3])),end="")
print(f"{Fore.RED} |{Fore.BLACK}",end="")
print("{:^13}".format("---->"),end="")
for col_sep in range(n//3):
print(f"{Fore.RED}|{Fore.BLACK} "+" | ".join((str(num) if num>0 else " " for num in solution[n//2,col_sep*n//3:(col_sep+1)*n//3])),end="")
print(f"{Fore.RED} |{Fore.BLACK}")
for row in range(n//2+1,n):
for col_sep in range(n//3):
print(f"{Fore.RED}|{Fore.BLACK} "+" | ".join((str(num) if num>0 else " " for num in puzzle[row,col_sep*n//3:(col_sep+1)*n//3])),end="")
print(f"{Fore.RED} |{Fore.BLACK}",end="")
print("\t\t",end="")
for col_sep in range(n//3):
print(f"{Fore.RED}|{Fore.BLACK} "+" | ".join((str(num) if num>0 else " " for num in solution[row,col_sep*n//3:(col_sep+1)*n//3])),end="")
print(f"{Fore.RED} |{Fore.BLACK}")
if (row+1)%3==0:
print(" "*(n)+"\t\t"+" "*(n))
else:
print(f"The sudoku\n{puzzle}\nis not solvable.")