Nqueens

N = 8 # (size of the chessboard) 

def solveNQueens(board, col): 

 if col == N: 

  print(board) 

  return True 

 for i in range(N): 

  if isSafe(board, i, col): 

   board[i][col] = 1 

   if solveNQueens(board, col + 1): 

    return True 

   board[i][col] = 0 

 return False 

def isSafe(board, row, col): 

 for x in range(col): 

  if board[row][x] == 1: 

   return False 

 for x, y in zip(range(row, -1, -1), range(col, -1, -1)): 

  if board[x][y] == 1: 

   return False 

 for x, y in zip(range(row, N, 1), range(col, -1, -1)): 

  if board[x][y] == 1: 

   return False 

 return True 

board = [[0 for x in range(N)] for y in range(N)] 

if not solveNQueens(board, 0): 

 print("No solution found")