#!/usr/bin/env python import heapq import sys from typing import Iterator, List, NamedTuple, Set class Point(NamedTuple): x: int y: int def solve(input: List[str]) -> int: def parse_levels() -> List[List[int]]: levels = [[int(c) for c in line] for line in input] width, height = len(levels), len(levels[0]) res = [[0 for j in range(width * 5)] for i in range(height * 5)] for i in range(height): for j in range(width): res[i][j] = levels[i][j] # Do first row of blocks for i in range(height): for j in range(width, width * 5): res[i][j] = res[i][j - width] % 9 + 1 for i in range(height, height * 5): for j in range(width * 5): res[i][j] = res[i - height][j] % 9 + 1 return res levels = parse_levels() def neighbours(p: Point) -> Iterator[Point]: for dx, dy in (-1, 0), (1, 0), (0, -1), (0, 1): x, y = p.x + dx, p.y + dy if x < 0 or x >= len(levels): continue if y < 0 or y >= len(levels[0]): continue yield Point(x, y) def djikstra(start: Point, end: Point) -> int: # Priority queue of (distance, point) queue = [(0, start)] seen: Set[Point] = set() while len(queue) > 0: dist, p = heapq.heappop(queue) if p == end: return dist # We must have seen p with a smaller distance before if p in seen: continue # First time encountering p, must be the smallest distance to it seen.add(p) # Add all neighbours to be visited for n in neighbours(p): heapq.heappush(queue, (dist + levels[n.x][n.y], n)) assert False # Sanity check return djikstra(Point(0, 0), Point(len(levels) - 1, len(levels[0]) - 1)) def main() -> None: input = [line.strip() for line in sys.stdin.readlines()] print(solve(input)) if __name__ == "__main__": main()