Aditya
37 lines
1.1 KiB
Python
37 lines
1.1 KiB
Python
def is_safe(board, row, col):
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for i in range(row):
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if board[i] == col or abs(board[i] - col) == abs(i - row):
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return False
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return True
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def solve_n_queens_first(board, row, n):
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if row == n:
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return board[:] # Return the first solution found
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for col in range(n):
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if is_safe(board, row, col):
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board[row] = col
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result = solve_n_queens_first(board, row + 1, n)
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if result: # If solution found, return immediately
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return result
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board[row] = -1 # Backtrack
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return None # No solution in this path
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def print_solution(board, n):
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for row in range(n):
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line = ['Q' if i == board[row] else '.' for i in range(n)]
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print(" ".join(line))
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print()
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def n_queens_one_solution(n):
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board = [-1] * n
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solution = solve_n_queens_first(board, 0, n)
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if solution:
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print("One valid n-Queens solution:")
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print_solution(solution, n)
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else:
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print("No solution exists.")
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# Example: 8-Queens
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n_queens_one_solution(8)
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