Advent of code

◂ 9 décembre 2022 ▸

  Rope Bridge : Corde qui bouge et tire la queue (snake)

L 2

D 2

L 2

R 2

L 1

1. code.py
2. snake.png
3. snake.py

DIRECTIONS = {'R':(1,0), 'L':(-1,0), 'U':(0,1), 'D':(0,-1)}

f = open("input.txt", 'r')
splittedLines = [line[:-1].split() for line in f.readlines()]
commands = map( lambda t:{'direction':DIRECTIONS[t[0]], 'nb':int(t[1])}, splittedLines)

def sign(x):  # ou utiliser numpy.sign
    return (x > 0 and 1) or (x < 0 and -1) or 0

# Version pour écarts d'au plus 2 entre deux bouts:
def updatePositionSimple(xHead, yHead, xTail, yTail):
    diffX = xHead - xTail
    diffY = yHead - yTail
    if (abs(diffX) <= 1) and (abs(diffY) <= 1):
        return (xTail, yTail)
    else:
        return (xTail + sign(diffX), yTail + sign(diffY))

# Version généralisée pour tout écart entre deux bouts:
def updatePosition(xHead, yHead, xTail, yTail):
    diffX = xHead - xTail
    diffY = yHead - yTail
    return (xTail + diffX - sign(diffX)*(abs(diffX) >= abs(diffY)), yTail + diffY - sign(diffY)*(abs(diffY) >= abs(diffX)))


positions = 10  *  [ (0,0) ]
# Partie 1
visitedT = { (0,0) }
# Partie 2
visited9 = { (0,0) }

for command in commands:
    for _ in range(command['nb']):
        positions[0]  =  ( positions[0][0] + command['direction'][0],  positions[0][1] + command['direction'][1] )
        for i in range(1, len(positions)):
            positions[i] = updatePosition(*positions[i-1], *positions[i])
        visitedT.add(positions[1])
        visited9.add(positions[-1])


print("Réponse partie 1:", len(visitedT))
print("Réponse partie 2:", len(visited9))