Solved 2024/14 P2

2024/14/14.md

@@ -156,8 +156,6 @@ after exactly 100 seconds have elapsed?*
 
 Your puzzle answer was `230686500`.
 
-The first half of this puzzle is complete! It provides one gold star: \*
-
 ## \-\-- Part Two \-\-- {#part2}
 
 During the bathroom break, someone notices that these robots seem
@@ -170,8 +168,14 @@ picture of a Christmas tree*.
 *What is the fewest number of seconds that must elapse for the robots to
 display the Easter egg?*
 
-Answer:
+Your puzzle answer was `7672`.
 
-Although it hasn\'t changed, you can still [get your puzzle
+Both parts of this puzzle are complete! They provide two gold stars:
+\*\*
+
+At this point, you should [return to your Advent calendar](/2024) and
+try another puzzle.
+
+If you still want to see it, you can [get your puzzle
 input](14/input).
 

2024/14/solution.py

@@ -1,13 +1,15 @@
 #!/bin/python3
 import sys,time,re
 from pprint import pprint
+from termcolor import colored
+
 sys.path.insert(0, '../../')
-from fred import list2int,get_re,lprint,loadFile,addTuples,grid_valid
+from fred import list2int,get_re,lprint,loadFile,addTuples,grid_valid,bfs,dfs,flood_fill
 start_time = time.time()
 
-# input_f = 'test'
-# size_r = 7
-# size_c = 11
+input_f = 'test'
+size_r = 7
+size_c = 11
 
 input_f = 'input'
 size_r = 103
@@ -15,13 +17,18 @@ size_c = 101
 
 grid = [['.']*size_c]*size_r
 
-def nprint(grid,pos,x):
+def nprint(grid,pos=None,x=None,positions:list=None):
     for r in range(size_r):
         for c in range(size_c):
-            if (c,r) == pos:
+            if (c,r) == pos and positions is None:
                 print(x,end='')
+            elif positions is not None:
+                if (c,r) in positions:
+                    print(x,end='')
+                else:
+                    print(colored(grid[r][c],'red'),end='')
             else:
-                print(grid[r][c],end='')
+                print(colored(grid[r][c],'red'),end='')
         print()
 
 #########################################
@@ -129,7 +136,54 @@ print('Part 1:',part1(), '\t\t', round((time.time() - start_time)*1000), 'ms')
 #                                       #
 #########################################
 def part2():
-    return
+    instructions = loadFile(input_f)
+    cords = []
+    for idx,inst in enumerate(instructions):
+        match = get_re(r"^p=(-?\d+),(-?\d+) v=(-?\d+),(-?\d+)",inst)
+        
+        instructions[idx] = [(int(match.group(1)),int(match.group(2))),(int(match.group(3)),int(match.group(4)))]
+        cords.append(instructions[idx][0])
     
+    count = 0
+    
+    def generate():
+        coordinates = {}
+        for idx,inst in enumerate(instructions):            
+            pos = inst[0]
+            vel = inst[1] 
+            
+            pos = addTuples(pos,vel)
+            if pos[0] < 0:
+                pos = (pos[0]+size_c,pos[1])
+            if pos[0] >= size_c:
+                pos = (pos[0]-size_c,pos[1])
+            if pos[1] < 0:
+                pos = (pos[0],pos[1]+size_r)
+            if pos[1] >= size_r:
+                pos = (pos[0],pos[1]-size_r)
+            instructions[idx] = [pos,vel]
+            cords[idx] = pos
+            if pos not in coordinates:
+                coordinates[pos] = 0
+            coordinates[pos] += 1
+        return coordinates
+    
+    while True:
+       
+        coordinates = generate()
+        
+        count += 1
+
+        visited = []
+        if 2 not in coordinates.values(): 
+            for pos in coordinates.keys():
+                if pos not in visited:
+                    t_visited = flood_fill(coordinates.keys(),pos)
+                    visited += t_visited
+                    
+                    if len(t_visited) > 10:
+                        nprint(grid,x='*',positions=coordinates)
+
+                        return count
 start_time = time.time()
 print('Part 2:',part2(), '\t\t', round((time.time() - start_time)*1000), 'ms')

fred.py

@@ -601,4 +601,64 @@ def bfs(start, is_goal, get_neighbors, max_depth=float('inf')):
                 new_path = path + [neighbor]
                 queue.append((neighbor, new_path, depth + 1))
     
-    return goal_nodes, paths_to_goal
+    return goal_nodes, paths_to_goal
+
+def dfs(grid:list, pos:set) -> list:
+    """
+    Perform a flood fill/dfs starting from the given position in the grid.
+
+    Args:
+        grid (list): 2D list representing the grid.
+        pos (tuple): Starting position (row, col) in the grid.
+
+    Returns:
+        list: List of visited positions.
+    """
+    rows, cols = len(grid), len(grid[0])
+    start_value = grid[pos[0]][pos[1]]
+    visited = set()
+    print(rows,cols,start_value)
+    def is_valid(r, c):
+        return 0 <= r < rows and 0 <= c < cols and (r, c) not in visited and grid[r][c] == start_value
+
+    def dfs(r, c):
+        visited.add((r, c))
+        for dr, dc in [(-1, 0), (1, 0), (0, -1), (0, 1)]:
+            nr, nc = r + dr, c + dc
+            if is_valid(nr, nc):
+                dfs(nr, nc)
+
+    dfs(pos[0], pos[1])
+    return list(visited)
+
+# Should probably be added to the regular dfs.
+def flood_fill(cells, pos):
+    """  
+    Perform a flood fill starting from the given position in a grid defined by a list of occupied cells.
+
+    Args:
+        cells (list): List of sets representing occupied positions in the grid.
+        pos (tuple): Starting position (row, col) in the grid.
+
+    Returns:
+        list: List of visited positions.
+    """
+    occupied = set(cells)  # Set of all occupied positions.
+    if pos not in occupied:
+        return 0, []
+
+    visited = set()
+
+    def is_valid(cell):
+        return cell in occupied and cell not in visited
+
+    def dfs(cell):
+        visited.add(cell)
+        r, c = cell
+        for dr, dc in [(-1, 0), (1, 0), (0, -1), (0, 1)]:
+            neighbor = (r + dr, c + dc)
+            if is_valid(neighbor):
+                dfs(neighbor)
+
+    dfs(pos)
+    return list(visited)