Card Puzzle

card-puzzle.py

# A solver for https://twitter.com/ikeikey/status/1543710547874615297
import numpy as np

def search(A, l_count, handlist, i, j):
    if i == 7 and j == 7:
        return A
    elif i == j:
        return search(A, l_count, handlist, i, j+1)

    l_count = list(l_count)
    handlist = list(handlist)
    handlist.append(None)
    A = np.array(A)
    for x in range(8):
        if x == i or x == j:
            continue
        if l_count[x] >= 7:
            continue
        if A[j,i] == x:
            continue
        hands = tuple(sorted([i,j,x]))
        if hands in handlist:
            continue
        handlist[-1] = hands
        l_count[x] += 1
        A[i,j] = x
        if j == 7:
            status = search(A, l_count, handlist, i+1, 0)
        else:
            status = search(A, l_count, handlist, i, j+1)
        if status is not None:
            return status
        l_count[x] -= 1
    return None


A = np.ones((8,8), dtype=np.int64) * -1
l_count = [0]*8
handlist = []
A = search(A, l_count, handlist, 0, 0)

print(A+1)

d_strategy = {}
for i in range(8):
    for j in range(8):
        answer = A[i,j]
        hands = tuple(sorted([i,j,answer]))
        assert hands not in d_strategy.keys()
        if answer != -1:
            d_strategy[hands] = (i,j), answer

print(len(d_strategy.keys()))

for k,v in sorted(d_strategy.items(), key=lambda x:x[0]):
    k  = tuple(np.array(k, dtype=np.int64)+1)
    v0 = tuple(np.array(v[0], dtype=np.int64)+1)
    v1 = v[1] + 1
    print(k, ":", v0, "->", v1)