diff --git a/2023/day23.py b/2023/day23.py
new file mode 100755
index 0000000..9e0e62d
--- /dev/null
+++ b/2023/day23.py
@@ -0,0 +1,179 @@
+#!/usr/bin/python3
+"""
+Jour 23 du défi Advent Of Code pour l'année 2023
+"""
+import os
+import heapq
+
+# Un peu chaotique là
+dir_ections ={
+    '^': (-1, 0),
+    'v': (1, 0),
+    '<': (0, -1),
+    '>': (0, 1)
+}
+
+directions = [(1, 0), (-1,0), (0, 1), (0, -1)]
+
+def read_sample():
+    """récupère les entrées depuis le fichier texte correspondant"""
+    filename = os.path.join(os.path.dirname(__file__ ), "inputs", "day23.txt")
+    with open(filename, 'r') as f:
+        sample = f.read().split('\n')
+    sample = [ [j for j in i] for i in sample if i != '' ]
+    return sample
+
+def find_start(sample):
+    """Départ du puzzle"""
+    for i in range(len(sample[0])):
+        if sample[0][i] == '.':
+            return (0, i)
+    raise NotImplementedError
+
+def find_end(sample):
+    """Arrivée du puzzle"""
+    for i in range(len(sample[-1])):
+        if sample[-1][i] == '.':
+            return (len(sample)-1, i)
+    raise NotImplementedError
+
+def valid(pos, sample):
+    """La position est bien dans la grille"""
+    return pos[0] >= 0 and pos[1] >= 0 and pos[0] < len(sample) and pos[1] < len(sample[0])
+
+
+def not_intersect(l1, l2):
+    """L'intersection de l1 et l2 est bien vide"""
+    return len(set(l1)&set(l2)) == 0
+
+def added_elems(pos, npos):
+    """Éléments vus en passant de pos à npos"""
+    if abs(npos[0]-pos[0])+abs(npos[1]-pos[1]) == 1:
+        return [npos]
+    p0 = (min(pos[0], npos[0]), min(pos[1], npos[1]))
+    p1 = (max(pos[0], npos[0]), max(pos[1], npos[1]))
+    elems = set()
+    for i in range(p1[0]-p0[0]+1):
+        for j in range(p1[1]-p0[1]+1):
+            elems.add((p0[0]+i, p0[1]+j))
+    return list(elems-{pos})
+
+
+def find_next(sample, i, j):
+    """Pourquoi en double ? je ne suis pas sûr duquel est exécuté donc je touche pas pour le moment"""
+    symb = sample[i][j]
+    dirt = dir_ections[symb]
+    i, j = i+dirt[0], j+dirt[1]
+    i, j = i+dirt[0], j+dirt[1]
+
+    return (i, j)
+
+def compress_voisins(i, j, sample, symbols={'.'}):
+    """Prochains voisins en sautant les longs tunnels"""
+    def two_dirs(pi, pj):
+        return len([(a, b) for a, b in directions if valid((pi+a, pj+b), sample) and sample[pi+a][pj+b] in symbols]) <= 2
+
+    v = set()
+    for d in directions:
+        pi, pj = i+d[0], j+d[1]
+        if valid((pi, pj), sample) and sample[pi][pj] in symbols:
+            while valid((pi, pj), sample) and sample[pi][pj] in symbols and two_dirs(pi, pj):
+                pi, pj = pi+d[0], pj+d[1]
+            if not two_dirs(pi, pj):
+                pi, pj = pi+d[0], pj+d[1]
+            v.add((pi-d[0], pj-d[1]))
+    return v
+
+def longest_hike(sample, start, end, part=1):
+    def find_next(sample, i, j): # Globalement inutile, je n'avais pas compris la question comme ça initialement
+        """Renvoie la position après avoir marché sur i, j"""
+        symb = sample[i][j]
+        dirt = dir_ections[symb]
+        i, j = i+dirt[0], j+dirt[1]
+        while valid((i, j), sample) and sample[i][j] != '#':
+            i, j = i+dirt[0], j+dirt[1]
+        i, j = i-dirt[0], j-dirt[1]
+        return (i, j)
+
+    def voisins(pos):
+        """Renvoie les "voisins" de pos, via compress_voisins notamment qui renvoie ~les voisins les plus loins~"""
+        v = set()
+        if part == 2:
+            return compress_voisins(pos[0], pos[1], sample, symbols={'^', 'v', '<', '>', '.'})-{pos}
+
+        potentials = [(pos[0]+1, pos[1]), (pos[0]-1, pos[1]), (pos[0], pos[1]+1), (pos[0], pos[1]-1)]
+        for i, j in potentials:
+            if valid((i, j), sample):
+                if sample[i][j] in {'^', 'v', '<', '>'}:
+                    nx = find_next(sample, i, j)
+                    v.add(nx)
+                
+        return (v|compress_voisins(pos[0], pos[1], sample)) -{pos}
+
+    # Cache voisins
+    pre_voisins = {}
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            if sample[i][j] in {'^', 'v', '<', '>', '.'}:
+                pre_voisins[(i, j)] = voisins((i, j))
+
+
+    to_end = []
+    current_max = 0
+
+    priority_queue = [(0, (start, [start]))]
+    while priority_queue:
+        popped = heapq.heappop(priority_queue)
+        dist, data = popped
+        pos, prev = data
+
+        for npos in pre_voisins[pos]:
+            if npos == end:
+                to_end.append((dist+abs(npos[0]-pos[0])+abs(npos[1]-pos[1]), [])) #! Faster to return [] but will loose the "good" return path
+                print("new end:", dist+abs(npos[0]-pos[0])+abs(npos[1]-pos[1]))
+                current_max = max(current_max, dist+abs(npos[0]-pos[0])+abs(npos[1]-pos[1]))
+
+            added = added_elems(pos, npos)
+            assert len(added) > 0
+            if not_intersect(added, prev) and valid(npos, sample):
+                heapq.heappush(priority_queue, (dist+abs(npos[0]-pos[0])+abs(npos[1]-pos[1]), (npos, prev+added)))
+
+
+    print([i[0] for i in to_end])
+    return max(to_end)
+
+
+def print_sol(solt, sample):
+    """Afficher une solution"""
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            if (i, j) in solt:
+                print('O', end='')
+            else:
+                print(sample[i][j], end='')
+        print()
+
+
+def part1(sample):
+    """Partie 1 du défi"""
+    start, end = find_start(sample), find_end(sample)
+    value, points = longest_hike(sample, start, end)
+    return value
+
+def part2(sample):
+    """Partie 2 du défi"""
+    # au bout de 1h20, 2378 seulement.
+    start, end = find_start(sample), find_end(sample)
+    value, points = longest_hike(sample, start, end, part=2)
+    #print_sol(points, sample)
+    return value
+
+
+def main():
+    """Fonction principale"""
+    sample = read_sample()
+    print(f"part1: {part1(sample)}")
+    print(f"part2: {part2(sample)}")
+
+if __name__ == "__main__":
+    main()