--- Day 4: Ceres Search ---

"Looks like the Chief's not here. Next!" One of The Historians pulls out a device and pushes the only button on it. After a brief flash, you recognize the interior of the Ceres monitoring station!

As the search for the Chief continues, a small Elf who lives on the station tugs on your shirt; she'd like to know if you could help her with her word search (your puzzle input). She only has to find one word: XMAS.

This word search allows words to be horizontal, vertical, diagonal, written backwards, or even overlapping other words. It's a little unusual, though, as you don't merely need to find one instance of XMAS - you need to find all of them. Here are a few ways XMAS might appear, where irrelevant characters have been replaced with .:

..X...
.SAMX.
.A..A.
XMAS.S
.X....
The actual word search will be full of letters instead. For example:

MMMSXXMASM
MSAMXMSMSA
AMXSXMAAMM
MSAMASMSMX
XMASAMXAMM
XXAMMXXAMA
SMSMSASXSS
SAXAMASAAA
MAMMMXMMMM
MXMXAXMASX
In this word search, XMAS occurs a total of 18 times; here's the same word search again, but where letters not involved in any XMAS have been replaced with .:

....XXMAS.
.SAMXMS...
...S..A...
..A.A.MS.X
XMASAMX.MM
X.....XA.A
S.S.S.S.SS
.A.A.A.A.A
..M.M.M.MM
.X.X.XMASX
Take a look at the little Elf's word search. How many times does XMAS appear?

Your puzzle answer was 2434.

--- Part Two ---

The Elf looks quizzically at you. Did you misunderstand the assignment?

Looking for the instructions, you flip over the word search to find that this isn't actually an XMAS puzzle; it's an X-MAS puzzle in which you're supposed to find two MAS in the shape of an X. One way to achieve that is like this:

M.S
.A.
M.S
Irrelevant characters have again been replaced with . in the above diagram. Within the X, each MAS can be written forwards or backwards.

Here's the same example from before, but this time all of the X-MASes have been kept instead:

.M.S......
..A..MSMS.
.M.S.MAA..
..A.ASMSM.
.M.S.M....
..........
S.S.S.S.S.
.A.A.A.A..
M.M.M.M.M.
..........
In this example, an X-MAS appears 9 times.

Flip the word search from the instructions back over to the word search side and try again. How many times does an X-MAS appear?
cont = [list(i.strip()) for i in open("day4input.txt").readlines()]

def get_neighbors(matrix, x, y):
    rows = len(matrix)
    cols = len(matrix[0])
    neighbors = []

    directions = [(-1, -1), (-1, 0), (-1, 1), (0, -1), (0,0), (0, 1), (1, -1), (1, 0), (1, 1)]
    
    for dx, dy in directions:
        nx, ny = x + dx, y + dy
        if 0 <= nx < rows and 0 <= ny < cols:
            neighbors.append(matrix[nx][ny])
    
    return neighbors

def check(matrix):
    ret = 0
    m = matrix.copy()
    mas = ["MAS", "SAM"]
    d = ''.join([m[0][0], m[1][1], m[2][2]])
    a = ''.join([m[0][2], m[1][1], m[2][0]])
    ret += 1 if (d in mas and a in mas) else 0
    return ret

t = 0

for x in range(len(cont)):
    for y in range(len(cont[x])):
        if x in [0, 139] or y in [0, 139]:
            continue
        if cont[x][y] == "A":
            neighbours = get_neighbors(cont, x,y)
            matrix = [neighbours[:3], neighbours[3:6], neighbours[6:]]

            t += check(matrix) 

print(t)