first commit

2024-10-23 18:44:54 -04:00
commit aeaa436c25
2935 changed files with 621866 additions and 0 deletions
--- a/pathfinding_algorithms.py
+++ b/pathfinding_algorithms.py
@@ -0,0 +1,122 @@
+# pathfinding_algorithms.py
+
+from collections import deque
+import heapq
+
+def get_adjacent_cells(cell, maze):
+    row, col = cell
+    directions = [(-1,0), (1,0), (0,-1), (0,1)]
+    neighbors = []
+    for dr, dc in directions:
+        r, c = row + dr, col + dc
+        if 0 <= r < maze.shape[0] and 0 <= c < maze.shape[1] and maze[r][c] == 0:
+            neighbors.append((r, c))
+    return neighbors
+
+def bfs_generator(maze, start, end):
+    queue = deque([start])
+    visited = set()
+    visited.add(start)
+    parent = {}
+    steps = 0
+
+    while queue:
+        current = queue.popleft()
+        steps += 1
+        yield ('visit', current, steps)
+        if current == end:
+            break
+        for neighbor in get_adjacent_cells(current, maze):
+            if neighbor not in visited:
+                queue.append(neighbor)
+                visited.add(neighbor)
+                parent[neighbor] = current
+                yield ('enqueue', neighbor, steps)
+
+    # Reconstruct path
+    path = []
+    if end in parent:
+        cell = end
+        while cell != start:
+            path.append(cell)
+            cell = parent[cell]
+        path.append(start)
+        path.reverse()
+        for cell in path:
+            yield ('path', cell, steps)
+    yield ('done', None, steps)
+
+def dfs_generator(maze, start, end):
+    stack = [start]
+    visited = set()
+    visited.add(start)
+    parent = {}
+    steps = 0
+
+    while stack:
+        current = stack.pop()
+        steps += 1
+        yield ('visit', current, steps)
+        if current == end:
+            break
+        for neighbor in reversed(get_adjacent_cells(current, maze)):
+            if neighbor not in visited:
+                stack.append(neighbor)
+                visited.add(neighbor)
+                parent[neighbor] = current
+                yield ('enqueue', neighbor, steps)
+
+    # Reconstruct path
+    path = []
+    if end in parent:
+        cell = end
+        while cell != start:
+            path.append(cell)
+            cell = parent[cell]
+        path.append(start)
+        path.reverse()
+        for cell in path:
+            yield ('path', cell, steps)
+    yield ('done', None, steps)
+
+def a_star_generator(maze, start, end):
+    heap = []
+    heapq.heappush(heap, (0, start))
+    came_from = {}
+    g_score = {start: 0}
+    f_score = {start: heuristic(start, end)}
+    steps = 0
+
+    while heap:
+        _, current = heapq.heappop(heap)
+        steps += 1
+        yield ('visit', current, steps)
+        if current == end:
+            break
+        for neighbor in get_adjacent_cells(current, maze):
+            tentative_g = g_score[current] + 1
+            if neighbor not in g_score or tentative_g < g_score[neighbor]:
+                came_from[neighbor] = current
+                g_score[neighbor] = tentative_g
+                f_score_neighbor = tentative_g + heuristic(neighbor, end)
+                f_score[neighbor] = f_score_neighbor
+                heapq.heappush(heap, (f_score_neighbor, neighbor))
+                yield ('enqueue', neighbor, steps)
+
+    # Reconstruct path
+    path = []
+    if end in came_from:
+        cell = end
+        while cell != start:
+            path.append(cell)
+            cell = came_from[cell]
+        path.append(start)
+        path.reverse()
+        for cell in path:
+            yield ('path', cell, steps)
+    yield ('done', None, steps)
+
+def heuristic(a, b):
+    # Manhattan distance
+    return abs(a[0] - b[0]) + abs(a[1] - b[1])
+