advent-of-code/2022/python/day14.py

import matrix
import shared
import itertools
import functools


SAND_START = [0,500]


def get_lines(rows):
    _rows = []
    for row in rows:
        _row = []
        for point in row.split(" -> "):
            _row.append(list(reversed(list(map(int, point.split(","))))))
        _rows.append(_row)
    return _rows

def find_bounds(lines):
    x = []
    y = []
    for line in lines:
        x.extend(matrix.split_x_out(line))
        y.extend(matrix.split_y_out(line))
    return shared.minmax(y),shared.minmax(x)

    
def part1(rows):
    def get_next(sand):
        next_y = sand[0]+1
        dl = sand[1]-1
        d = sand[1]
        dr = sand[1]+1
        return next_y, (dl,d,dr)
    lines = get_lines(rows)
    (minY,maxY), (minX,maxX) = find_bounds(lines)
    mx = matrix.matrix_of_size(maxX+2,maxY+2)
    walls = []
    for line in lines:
        for x in range(len(line)-1):
            coords = matrix.coords_between_points(line[x], line[x+1])
            walls.extend(coords)
    for y,x in walls:
        mx[y][x] = "#"
    mx[SAND_START[0]][SAND_START[1]] = "+"

    sands = []

    try:
        for sand_grains in range(900): # produce Sand one unit at a time
            last_grain = []
            sand = SAND_START[:]
            #print("starting sand", sand_grains+1, sand)
            while True:
                last_grain.append(sand[:])
                next_y, (dl, d, dr) = get_next(sand)
                if mx[next_y][d] == 0:
                    #print(mx[next_y][d],"moving_down", end=' ')
                    #print("moving down")
                    sand[0] = next_y
                elif mx[next_y][dl] == 0:
                    #print(mx[next_y][dl], "moving left", end=' ')
                    #print("moving left")
                    sand[0] = next_y
                    sand[1] = dl
                elif mx[next_y][dr] == 0:
                    #print(mx[next_y][dr], "moving right", end=' ')
                    #print("moving right")
                    sand[0] = next_y
                    sand[1] = dr
                else:
                    mx[sand[0]][sand[1]] = "o"
                    #print(mx[next_y][dl], mx[next_y][d], mx[next_y][dr])
                    #print("STOPPING", end=' ')
                    break
            #matrix.view_matrix(mx, 0,minX-1, maxY+1,maxX+2)
    except IndexError:
        sands.append(last_grain)
        for y,x in sands[-1]:
            mx[y][x] = "~"
        #matrix.view_matrix(mx, 0,minX-1, maxY+1,maxX+2)
        print("done", sand_grains)


def part2(rows):
    def get_next(sand):
        next_y = sand[0]+1
        dl = sand[1]-1
        d = sand[1]
        dr = sand[1]+1
        return next_y, (dl,d,dr)
    def check_air(y,x):
        if y == floor:
            return False
        if (y,x) in walls:
            return False
        return True

    lines = get_lines(rows)
    (minY,maxY), (minX,maxX) = find_bounds(lines)
    walls = set()
    for line in lines:
        for x in range(len(line)-1):
            coords = matrix.coords_between_points(line[x], line[x+1])
            for c in coords:
                walls.add(c)
    for y,x in walls:
        walls.add((y,x))
    floor = maxY + 2

    sand_grains = -1
    while True:
        sand_grains += 1
        sand = [0,500]
        if tuple(sand) in walls:
            print("done", sand_grains)
            break
        while True:
            next_y, (dl, d, dr) = get_next(sand)
            if check_air(next_y, d):
                sand[0] = next_y
            elif check_air(next_y,dl):
                sand[0] = next_y
                sand[1] = dl
            elif check_air(next_y, dr):
                sand[0] = next_y
                sand[1] = dr
            else:
                walls.add(tuple(sand))
                break
        #matrix.view_matrix(mx, 0,minX-1, maxY+3,maxX+2)



def main():
    rows = [row for row in shared.load_rows(14)]
    with shared.elapsed_timer() as elapsed:
        part1(rows)
        print("🕒", elapsed())
    with shared.elapsed_timer() as elapsed:
       part2(rows)
       print("🕒", elapsed())


if __name__ == "__main__":
    main()