day13pt2.py

day13pt2.py

filename = '13.txt'
class Grid():
    def __init__(self, max_x, max_y, coords, folds):
        self.max_x = max_x
        self.max_y = max_y
        self.coords = coords
        self.folds = folds
        self.map = None

        self.build_map()

    def __repr__(self):
        return '\n'.join([''.join(r) for r in self.map])

    def build_map(self):
        template = [
            ['.' for _ in range(self.max_x + 1)]
            for _ in range(self.max_y + 1)]
        for coord in coords:
            template[coord[1]][coord[0]] = '#'
        self.map = template

    def fold_all(self):
        while self.folds:
            self.fold()

    def fold(self):
        letter, num = self.folds.pop(0)
        if letter == 'x':
            self.fold_left(num)
        else:
            self.fold_up(num)

    def fold_up(self, fold_row):
        top_half = self.map[:fold_row]
        bottom_half = list(reversed(self.map[fold_row:]))
        new_map = []

        for i in range(fold_row):
            new_row = [
                '#' if '#' in [top_half[i][j], bottom_half[i][j]] else '.'
                for j in range(len(top_half[i]))
            ]
            new_map.append(new_row)
        self.map = new_map

    def fold_left(self, fold_col):
        new_map = []

        for row in self.map:
            left_half = row[:fold_col]
            right_half = list(reversed(row[fold_col:]))

            new_row = ['#' if '#' in [left_half[i], right_half[i]] else '.'
                for i in range(len(left_half))]
            new_map.append(new_row)
        self.map = new_map

    def count_dots(self):
        dots = 0
        for row in self.map:
            for c in row:
                dots += 1 if c == '#' else 0
        return dots


coords = []
folds = []
max_x = 0
max_y = 0
with open(filename, 'r') as f:
    for line in f:
        if ',' in line:
            new_coord = [int(n) for n in line.strip().split(',')]
            max_x = max(max_x, new_coord[0])
            max_y = max(max_y, new_coord[1])
            coords.append(new_coord)
        elif 'fold' in line:
            directions = line.strip().split('=')
            folds.append((directions[0][-1], int(directions[1])))

grid = Grid(max_x, max_y, coords, folds)
grid.fold_all()
print(grid)