What are some examples of backtracking in Python?

What are some examples of backtracking in Python?

Backtracking is a problem-solving technique that involves exploring all possible solutions and abandoning those that fail to satisfy the constraints. A classic example in Python is solving the N-Queens problem.

Can you show me the code for the N-Queens problem?

Sure! Here's a simple implementation of the N-Queens problem using backtracking in Python:

def solve_n_queens(n):
    def is_safe(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 solve(board, col):
        if col >= n:
            return True
        for i in range(n):
            if is_safe(board, i, col):
                board[i][col] = 1
                if solve(board, col + 1):
                    return True
                board[i][col] = 0
        return False

    board = [[0] * n for _ in range(n)]
    if not solve(board, 0):
        return []
    return board

# Example usage:
print(solve_n_queens(4))

What other problems can be solved using backtracking?

Other problems that can be solved using backtracking include the Sudoku solver, the Hamiltonian path problem, and generating permutations or combinations of a set.