diff options
Diffstat (limited to '17_2023.py')
-rw-r--r-- | 17_2023.py | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/17_2023.py b/17_2023.py new file mode 100644 index 0000000..5ba5030 --- /dev/null +++ b/17_2023.py @@ -0,0 +1,49 @@ +import sys +import re +from copy import deepcopy +from math import gcd +from collections import defaultdict, Counter, deque +import heapq + +D = open(sys.argv[1]).read().strip() +L = D.split("\n") +G = [[c for c in row] for row in L] +R = len(G) +C = len(G[0]) + + +def solve(part2): + Q = [(0, 0, 0, -1, -1)] + D = {} + while Q: + dist, r, c, dir_, indir = heapq.heappop(Q) + if (r, c, dir_, indir) in D: + continue + D[(r, c, dir_, indir)] = dist + for i, (dr, dc) in enumerate([[-1, 0], [0, 1], [1, 0], [0, -1]]): + rr = r + dr + cc = c + dc + new_dir = i + new_indir = 1 if new_dir != dir_ else indir + 1 + + isnt_reverse = (new_dir + 2) % 4 != dir_ + + isvalid_part1 = new_indir <= 3 + isvalid_part2 = new_indir <= 10 and ( + new_dir == dir_ or indir >= 4 or indir == -1 + ) + isvalid = isvalid_part2 if part2 else isvalid_part1 + + if 0 <= rr < R and 0 <= cc < C and isnt_reverse and isvalid: + cost = int(G[rr][cc]) + heapq.heappush(Q, (dist + cost, rr, cc, new_dir, new_indir)) + + ans = 1e9 + for (r, c, dir_, indir), v in D.items(): + if r == R - 1 and c == C - 1: + ans = min(ans, v) + return ans + + +print(solve(False)) +print(solve(True)) |