20-11

20/20-11.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+from collections import defaultdict
+
+#file = "./input.txt"
+#cheat_time = 100
+file = "./ex.txt"
+cheat_time = 25
+
+from time import time
+from copy import deepcopy
+import heapq
+start_time = time()
+
+def print_grid(f):
+    for r in f:
+        for s in r:
+            print(s, end="")
+        print()
+
+def fill_grid(gri:list[list[str]], ma:list[tuple[int,int]], filler:str)->list[list[str]]:
+    result = deepcopy(gri)
+    for m in ma:
+        x , y = m[0],m[1]
+        result[y][x] = filler
+    return result
+
+
+def read_input(input_file:str, ) -> list[list[str]]:
+    result_grid = []
+    f = open(input_file, "r")
+    for line in f:
+        line = line.strip()
+        if line == "":
+            continue
+        else:
+            temp = []
+            for b in line:
+                temp.append(b)
+            result_grid.append(temp)
+    f.close()
+    return result_grid
+
+def find_start_end(maze:list[list[str]])->tuple[tuple[int,int],tuple[int,int]]:
+    rows, cols = len(maze), len(maze[0])
+    for r in range(rows):
+        for c in range(cols):
+            if maze[r][c] == 'S':
+                start_point = (r, c)
+            elif maze[r][c] == 'E':
+                end_point = (r, c)
+    return start_point, end_point
+
+def shortest_path(maze,start,end):
+    rows, cols = len(maze), len(maze[0])
+    # Dijkstra-Algorithmus
+    queue = [(0, start, [])]
+    visited = set()
+    while queue:
+        distance, current, path = heapq.heappop(queue)
+        if current == end:
+            # return distance, path + [current]
+            return distance, [(y, x) for x, y in path + [current]]
+        if current in visited:
+            continue
+        visited.add(current)
+        for dx, dy in [(0, 1), (1, 0), (0, -1), (-1, 0)]:
+            nx, ny = current[0] + dx, current[1] + dy
+            if 0 <= nx < rows and 0 <= ny < cols and maze[nx][ny] != '#':
+                heapq.heappush(queue, (distance + 1, (nx, ny), path + [current]))
+    return None, []
+
+if __name__ == "__main__":
+    grid  = read_input(file)
+    p_start, p_end = find_start_end(grid)
+    sol = shortest_path(grid, p_start, p_end)
+    full_path_len = sol[0]
+    #print(sol)
+    #print(f"Shortest Path Length: {sol[0]}")
+    #print_grid(fill_grid(grid,sol[1],"O"))
+    counts = defaultdict(int)
+    for i in range(1,len(grid)-1):
+        for j in range(1,len(grid[0])-1):
+            if grid[i][j] == "#":
+                grid[i][j] = "."
+                t_sol = shortest_path(grid, p_start, p_end)
+                if t_sol and t_sol[0] < sol[0]:
+                    counts[abs(t_sol[0]-sol[0])] += 1
+                grid[i][j] = "#"
+    p1_solution = 0
+    print(counts)
+    for key in counts.keys():
+        if key >= cheat_time:
+            p1_solution += counts[key]
+    print(f"Solution Part 1: {p1_solution}")
+    print(f'Runtime: {time()-start_time:.4f} s')