zax2002

import numpy as np

a, b, c = np.random.randint(0, 256, 3, dtype=np.uint8)

palette = [ [a, b, c], [a, a, b], [c, a, b], [b, a, c], [c, c, a] ]

rgb_img = [
  [ (a+3, b-2, c-1), (a, a+1, b-2), (c+2, a, b-3) ],
  [ (b, a-2, c+1), (c, c+2, a-1), (b-1, a, c-3) ],
  [ (a, a+1, b-2), (a+2, b-2, c-1), (c+1, c+1, a-2) ]
]

palette = np.array(palette).reshape(1, 1, 5, 3)
rgb_img = np.array(rgb_img).reshape(3, 3, 1, 3)
indices = np.linalg.norm(palette - rgb_img, axis=-1).argmin(axis=-1).ravel()

print(indices)

from sklearn.cluster import KMeans

a, b, c = np.random.randint(0, 256, 3, dtype=np.uint8)

palette = [ [a, b, c], [a, a, b], [c, a, b], [b, a, c], [c, c, a] ]

rgb_img = [
  [ (a+3, b-2, c-1), (a, a+1, b-2), (c+2, a, b-3) ],
  [ (b, a-2, c+1), (c, c+2, a-1), (b-1, a, c-3) ],
  [ (a, a+1, b-2), (a+2, b-2, c-1), (c+1, c+1, a-2) ]
]

result = (
    KMeans(n_clusters=len(palette), init=np.array(palette), n_init=1)
    .fit_transform(np.array(rgb_img).reshape(-1, 3))
    .argmin(axis=-1)
)

$connect = file_get_contents('https://accounts.e-autopay.com/external/widgets/pincodes/246928');
$num = explode('\'', $connect)[1];
echo $num; /* 21 */