https://twitter.com/yancya/status/1552495469297008643

nqueens.py

# -*- coding: utf-8 -*-

import itertools

def is_conflicted(qs, x ,y):
    for (v, w) in qs:
        if v == x or w == y or abs(v - x) == abs (w - y):
            return True

def solve(N, n, qs):
    if n == 0:
        return qs
    for pos in itertools.product(range(N - n, N), range(N)):
        if pos not in qs and not is_conflicted(qs, *pos):
            r = solve(N, n - 1, (*qs, pos))
            if r:
                return r

if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser(description='solve N queens puzzle')
    parser.add_argument('N', metavar='N', type=int, nargs='?', default=8, help='num queens')
    args = parser.parse_args()
    print(solve(args.N, args.N, ()))