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| author | Louis Burda <quent.burda@gmail.com> | 2020-12-08 21:53:34 +0100 |
|---|---|---|
| committer | Louis Burda <quent.burda@gmail.com> | 2020-12-08 21:53:34 +0100 |
| commit | 61c19fd58a9c32919b9b06d38dd9ba202cf43bfb (patch) | |
| tree | 716d58ee8979d3df123acfedcd5cb8472722d422 /src/13/solve.py | |
| download | aoc2018-python-61c19fd58a9c32919b9b06d38dd9ba202cf43bfb.tar.gz aoc2018-python-61c19fd58a9c32919b9b06d38dd9ba202cf43bfb.zip | |
Solve 25 days
Diffstat (limited to 'src/13/solve.py')
| -rw-r--r-- | src/13/solve.py | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/13/solve.py b/src/13/solve.py new file mode 100644 index 0000000..f8a4ac3 --- /dev/null +++ b/src/13/solve.py @@ -0,0 +1,167 @@ +from sys import argv as args
+
+f = open("input.txt")
+contents = f.read()
+test_contents = """
+/>-<\\
+| |
+| /<+-\\
+| | | v
+\\>+</ |
+ | ^
+ \\<->/
+"""
+
+tmap = [list(l) for l in contents.split("\n") if len(l) != 0]
+xlen = len(tmap[0])
+ylen = len(tmap)
+f.close()
+
+arrows = dict()
+arrows["<"] = (-1, 0)
+arrows[">"] = (1, 0)
+arrows["^"] = (0, -1)
+arrows["v"] = (0, 1)
+
+directions = [(-1,0), (0,-1), (1, 0), (0, 1)] # l - u - r - d
+
+def checkPos(x,y):
+ if x < xlen and x >= 0 and y < ylen and y >= 0:
+ return tmap[y][x]
+ return " "
+
+def correct(x, y):
+ cr = checkPos(x+1, y)
+ cl = checkPos(x-1, y)
+ cu = checkPos(x, y-1)
+ cd = checkPos(x, y+1)
+
+ if cr == "|": cr = " "
+ if cl == "|": cl = " "
+ if cu == "-": cu = " "
+ if cd == "-": cd = " "
+
+ r = cr != " "
+ l = cl != " "
+ u = cu != " "
+ d = cd != " "
+
+ sum = r + l + u + d
+
+ if sum > 2:
+ return "+"
+
+ # 2 around
+ if r:
+ if l:
+ return "-"
+ elif u:
+ return "/"
+ else:
+ return "\\"
+ else:
+ if not l:
+ return "|"
+ elif u:
+ return "/"
+ else:
+ return "\\"
+
+carts = list()
+for y in range(ylen):
+ for x in range(xlen):
+ if tmap[y][x] in arrows:
+ carts.append([x, y, arrows[tmap[y][x]], 0, 0])
+ tmap[y][x] = correct(x,y)
+
+def cartAt(x, y):
+ global carts
+ for i in range(len(carts)):
+ c = carts[i]
+ if c[0] == x and c[1] == y and not c[4]:
+ return i
+ return None
+
+def drawMap():
+ for y in range(ylen):
+ print("".join(["#" if cartAt(x,y) != None else tmap[y][x] for x in range(len(tmap[y]))]))
+
+def advance(cart):
+ ncart = [0 for x in range(5)]
+ ncart[0] = cart[0]+cart[2][0]
+ ncart[1] = cart[1]+cart[2][1]
+ col = cartAt(ncart[0], ncart[1])
+ if col != None:
+ return ncart[0], ncart[1], col
+
+ c = tmap[ncart[1]][ncart[0]]
+ d = directions.index(cart[2])
+
+ if c == "+":
+ d = (d + len(directions)-1 + cart[3]) % len(directions)
+ ncart[2] = directions[d]
+ ncart[3] = (cart[3] + 1) % 3
+ else: #dont need to change direction for '-' and '|'
+ if c == "/":
+ ncart[2] = directions[3-d]
+ elif c == "\\":
+ if d == 0: #l
+ ncart[2] = directions[1]
+ elif d == 1: #u
+ ncart[2] = directions[0]
+ elif d == 2: #r
+ ncart[2] = directions[3]
+ elif d == 3: #d
+ ncart[2] = directions[2]
+ else:
+ ncart[2] = cart[2]
+ ncart[3] = cart[3]
+ return ncart
+
+
+def solve1():
+ global carts
+
+ crash = None
+ while not crash:
+ carts = sorted(carts, key=lambda x:(x[0], x[1]))
+ for c in range(len(carts)):
+ nc = advance(carts[c])
+ if len(nc) == 3:
+ crash = nc
+ break
+ else:
+ carts[c] = nc
+
+ print(f"{crash[0]},{crash[1]}")
+
+def solve2():
+ global carts
+
+ while len(carts) > 1:
+ carts = sorted(carts, key=lambda x:(x[0], x[1]))
+ rcarts = list()
+ for c in range(len(carts)):
+ if carts[c][4]: continue;
+ nc = advance(carts[c])
+ if len(nc) == 3:
+ carts[c][4] = 1
+ carts[nc[2]][4] = 1
+ rcarts.append(carts[c])
+ rcarts.append(carts[nc[2]])
+ else:
+ carts[c] = nc
+ for c in rcarts:
+ if c in carts: # prevent doubles
+ carts.remove(c)
+
+ print(f"{carts[0][0]},{carts[0][1]}")
+
+def main():
+ if len(args) == 2:
+ if args[1] == "1":
+ solve1()
+ elif args[1] == "2":
+ solve2()
+
+main()
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