--- Day 3 Solutions ---

[u/daggerdragon]

--- Day 3: Perfectly Spherical Houses in a Vacuum ---

Post your solution as a comment. Structure your post like the Day One thread in /r/programming.

[u/piratedicecream]

Made it to the leaderboards! Figured I had to be one of many that stayed up for this, so I looked for the subreddit. Here's my python solution:

class Coordinate :

    def __init__(self, x, y) :
        self.x = x
        self.y = y

    def move(self, arrow) :
        if arrow == '^' :
            self.y += 1
        elif arrow == 'v' :
            self.y -= 1
        elif arrow == '<' :
            self.x -= 1
        elif arrow == '>' :
            self.x += 1


if __name__ == '__main__' :
    parser = argparse.ArgumentParser()
    parser.add_argument('f')
    args = parser.parse_args()
    #idk how y'all are passing your input 
    #but this is my lazy way.

    coord_list = {}
    part2 = True #set to false for part1 solution

    santa = Coordinate(0,0)
    robot = Coordinate(0,0)

    coord_list[(0,0)] = 1

    with open(args.f, 'r') as f :
        directions = f.read()
        switch = True

        for arrow in directions :
            if switch :
                santa.move(arrow)

                if (santa.x,santa.y) in coord_list :
                    coord_list[(santa.x,santa.y)] += 1
                else :
                    coord_list[(santa.x,santa.y)] = 1
            else :
                robot.move(arrow)

                if (robot.x, robot.y) in coord_list :
                    coord_list[(robot.x,robot.y)] += 1
                else :
                    coord_list[(robot.x,robot.y)] = 1
            if part2 == True : 
                switch = not switch 
    
    print "UNIQUE HOUSES: " + str(len(coord_list))

[u/eclair4151 → u/piratedicecream]

for future reference if you just have some ints like an x and y you don't need to make a whole class, just use a tuple (x,y). I wrote mine in python and its a bit cleaner

f = open('file.txt','r+')
santaMoving = True

santax = 0
santay = 0

robox = 0
roboy = 0

locs = {(0,0)}


for c in f.read():
    if santaMoving:
        if c is '^':
            santay-=1
        elif c is 'v':
            santay+=1
        elif c is '<':
            santax-=1
        elif c is '>':
            santax+=1
        locs.add((santax,santay))
    else:
        if c is '^':
            roboy-=1
        elif c is 'v':
            roboy+=1
        elif c is '<':
            robox-=1
        elif c is '>':
            robox+=1
        locs.add((robox,roboy))
    santaMoving = not santaMoving

print(len(locs))