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NQueens.py
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global N
N = 4
def printSolution(board):
for i in range(N):
for j in range(N):
print (board[i][j], end = " ")
print()
def isSafe(board, row, col):
for i in range(col):
if board[row][i] == 1:
return False
for i, j in zip(range(row, -1, -1),
range(col, -1, -1)):
if board[i][j] == 1:
return False
for i, j in zip(range(row, N, 1),
range(col, -1, -1)):
if board[i][j] == 1:
return False
return True
def solveutil(board, col):
if col >= N:
return True
for i in range(N):
if isSafe(board, i, col):
board[i][col] = 1
if solveutil(board, col + 1) == True:
return True
board[i][col] = 0
return False
def solveNQ():
board = [ [0, 0, 0, 0],
[0, 0, 0, 0],
[0, 0, 0, 0],
[0, 0, 0, 0] ]
if solveutil(board, 0) == False:
print ("Solution does not exist")
return False
printSolution(board)
return True
solveNQ()