Update README.md

2023/day21.py

@@ -3,7 +3,7 @@
 Jour 21 du défi Advent Of Code pour l'année 2023
 """
 import os
-from tqdm import tqdm
+from aoc_utils.decorators import timeit
 
 def read_sample():
     """récupère les entrées depuis le fichier texte correspondant"""
@@ -23,10 +23,11 @@ def do_steps(sample, steps=26501365, ext=False):
                 if sample[i][j] == 'S':
                     return (i, j)
 
-    def valid(pos):
+    def valid(pos, ext=False):
+        if ext:
+            return True
         return pos[0] >= 0 and pos[1] >= 0 and pos[0] < len_sample and pos[1] < len_sample0
 
-
     def is_point(pos, ext=False):
         if not ext and valid(pos):
             if sample[pos[0]][pos[1]] == '.' or sample[pos[0]][pos[1]] == 'S':
@@ -39,43 +40,62 @@ def do_steps(sample, steps=26501365, ext=False):
     def voisins(pos, ext=False):
         i, j = pos
         v = []
-        if valid((i, j-1)) and is_point((i, j-1), ext=ext):
+        if valid((i, j-1), ext=ext) and is_point((i, j-1), ext=ext):
             v.append((i, j-1))
-        if valid((i-1, j)) and is_point((i-1, j), ext=ext):
+        if valid((i-1, j), ext=ext) and is_point((i-1, j), ext=ext):
             v.append((i-1, j))
-        if valid((i, j+1)) and is_point((i, j+1), ext=ext):
+        if valid((i, j+1), ext=ext) and is_point((i, j+1), ext=ext):
             v.append((i, j+1))
-        if valid((i+1, j)) and is_point((i+1, j), ext=ext):
+        if valid((i+1, j), ext=ext) and is_point((i+1, j), ext=ext):
             v.append((i+1, j))
         return v
 
     i, j = find_S()
-    pos_ts = {(i, j): [(0, 0)]}
-    for i in tqdm(range(steps)):
-        new_pos_ts = {}
-        for pos in pos_ts.keys():
+    pos_ts = {(i, j)}
+    for i in range(steps):
+        new_pos_ts = set()
+        for pos in pos_ts:
             for p in voisins(pos, ext=ext):
-                mp = (p[0]%len_sample, p[1]%len_sample0)
-                tile = (p[0]//len_sample, p[1]//len_sample0)
-                if mp not in new_pos_ts.keys():
-                    new_pos_ts[mp] = []
-                for elem in pos_ts[pos]:
-                    t = (tile[0]+elem[0], tile[1]+elem[1])
-                    if t not in new_pos_ts[mp]:
-                        new_pos_ts[mp].append(t)
+                new_pos_ts.add(p)
 
         pos_ts = new_pos_ts
     return pos_ts
 
 
+def lagrange_interpolation(points, x0):
+    result = 0
+    for i in range(len(points)):
+        temp = points[i][1]
+        for j in range(len(points)):
+            if j != i:
+                temp *= (x0 - points[j][0]) / (points[i][0] - points[j][0])
+
+        result += temp
+
+    return int(result)
+
+@timeit
 def part1(sample):
     """Partie 1 du défi"""
-    return sum([len(i) for i in do_steps(sample, steps=64, ext=False).values()])
+    return len(do_steps(sample, steps=64, ext=False))
 
+@timeit
 def part2(sample):
     """Partie 2 du défi"""
-    print("WARNING, this will take a lot of time (and could not even work)")
-    return sum([len(i) for i in do_steps(sample, ext=True).values()])
+    def challenge(steps):
+        return len(do_steps(sample, steps=steps, ext=True))
+
+
+    half_size = len(sample)//2
+    size = len(sample)
+    points = [
+        (half_size, challenge(half_size)),
+        (half_size+size, challenge(half_size+size)),
+        (half_size+2*size, challenge(half_size+2*size))
+    ]
+    return lagrange_interpolation(points, 26501365)
+
+
 
 
 def main():

README.md

@@ -7,7 +7,7 @@
 2020: ***~.....................
 2021: *******~~~...............
 2022: ***************~.*..*....
-2023: **********...............
+2023: **********************~..
 
 .: nothing
 ~: 1 star
@@ -20,9 +20,17 @@ Add this to your `.bashrc`:
 AOC_PATH=$HOME/path/to/this/repo/
 alias aoc="$AOC_PATH/utils/cli.py"
 aoc-new () {
+  # To create a new day
   cd $AOC_PATH
   PATH="$PATH:$AOC_PATH"
-  $AOC_PATH/new_day.sh
-  PS1="$PS1[aoc] "
+  $AOC_PATH/utils/new_day.sh
+  export PYTHONPATH="$PYTHONPATH:$AOC_PATH"
+}
+
+aoc-env () {
+  # To load the AoC environment
+  cd $AOC_PATH
+  PATH="$PATH:$AOC_PATH"
+  export PYTHONPATH="$PYTHONPATH:$AOC_PATH"
 }
 ```

aoc_utils/constants.py

@@ -0,0 +1,13 @@
+arrows_dir ={
+    '^': (-1, 0),
+    'v': (1, 0),
+    '<': (0, -1),
+    '>': (0, 1)
+}
+
+cardinal_dir = [
+    (1, 0),
+    (-1,0),
+    (0, 1),
+    (0, -1)
+]

aoc_utils/decorators.py

@@ -0,0 +1,13 @@
+from functools import cache, wraps
+import time
+
+def timeit(func):
+    @wraps(func)
+    def timeit_wrapper(*args, **kwargs):
+        start_time = time.perf_counter()
+        result = func(*args, **kwargs)
+        end_time = time.perf_counter()
+        total_time = end_time - start_time
+        print(f'===== {func.__name__}: {total_time:.4f}s =====')
+        return result
+    return timeit_wrapper