diff --git a/2022/day12.py b/2022/day12.py
new file mode 100755
index 0000000..32e9d2f
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+++ b/2022/day12.py
@@ -0,0 +1,162 @@
+#!/usr/bin/python3
+"""
+Jour 12 du défi Advent Of Code pour l'année 2022
+"""
+import copy # pour deepcopy
+
+def read_sample():
+    """récupère les entrées depuis le fichier texte correspondant"""
+    with open('inputs/day12.txt', 'r') as f:
+        sample = f.read().split('\n')
+    sample = [ [j for j in i] for i in sample if i != '' ]
+    return sample
+
+def elevation(char):
+    return ord(char) - ord('a')
+
+
+def direction(sample, i, j):
+    dirs = []
+    if i > 0 :
+        hdiff = (elevation(sample[i-1][j]) - elevation(sample[i][j]))
+        if hdiff <= 1:
+            dirs.append('up')
+    if j > 0:
+        hdiff = (elevation(sample[i][j-1]) - elevation(sample[i][j]))
+        if hdiff <= 1:
+            dirs.append('left')
+    if i < len(sample)-1 :
+        hdiff = (elevation(sample[i+1][j]) - elevation(sample[i][j]))
+        if hdiff <= 1:
+            dirs.append('down')
+    if j < len(sample[0])-1:
+        hdiff = (elevation(sample[i][j+1]) - elevation(sample[i][j]))
+        if hdiff <= 1:
+            dirs.append('right')
+
+    if len(dirs)==0:
+        return []
+    return dirs
+
+def better_height(moves, heights, i, j, sample):
+    available = []
+    if heights[i][j] != -1:
+        available.append(heights[i][j])
+    if i > 0 :
+        if ('down' in moves[i-1][j] and heights[i-1][j] != -1):
+            available.append(heights[i-1][j]+1)
+    if j > 0:
+        if ('right' in moves[i][j-1] and heights[i][j-1] != -1):
+            available.append(heights[i][j-1]+1)
+    if i < len(sample)-1 :
+        if ('up' in moves[i+1][j] and heights[i+1][j] != -1):
+            available.append(heights[i+1][j]+1)
+    if j < len(sample[0])-1:
+        if ('left' in moves[i][j+1] and heights[i][j+1] != -1):
+            available.append(heights[i][j+1]+1)
+    
+    if len(available) == 0:
+        return -1
+    return min(available)
+
+
+def update_heights(moves, heights, sample):
+    changed = False
+    heights_c = copy.deepcopy(heights)
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            heights_c[i][j] = better_height(moves, heights, i, j, sample)
+            changed = changed or (heights_c[i][j] != heights[i][j])
+
+    return heights_c, changed
+
+def print_val(sample, heights):
+    """Afficher l'état actuel des chemins découverts"""
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            if heights[i][j] != -1:
+                print(f"\x1b[38;2;{heights[i][j]};{heights[i][j]};{heights[i][j]}m", end='')
+            else:
+                print("\x1b[38;2;0;0;0m", end='')
+            print("#", end='')
+        print("\033[0m")
+
+
+def part1(sample):
+    """Partie 1 du défi"""
+    start = (-1, -1)
+    end = (-1, -1)
+    # Récupère le début et la fin
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            if sample[i][j] == 'E':
+                end = (i, j)
+                sample[i][j] = 'z'
+            elif sample[i][j] == 'S':
+                start = (i, j)
+                sample[i][j] = 'a'
+
+    moves = [['.' for _ in range(len(sample[0]))] for _ in range(len(sample))]
+    # Calcul des positions directement accessibles
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            moves[i][j] = direction(sample, i, j)
+
+    # Initialisation des hauteurs
+    heights = [[-1 for _ in range(len(sample[0]))] for _ in range(len(sample))]
+    heights[start[0]][start[1]] = 0
+
+    steps = 0
+    changed = True
+    while heights[end[0]][end[1]] == -1 and changed:
+        steps += 1
+        heights, changed = update_heights(moves, heights, sample)
+
+        #print_val(sample, heights)
+
+    return heights[end[0]][end[1]]
+
+def part2(sample):
+    """Partie 2 du défi"""
+    start = (-1, -1)
+    end = (-1, -1)
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            if sample[i][j] == 'E':
+                end = (i, j)
+                sample[i][j] = 'z'
+            elif sample[i][j] == 'S':
+                start = (i, j)
+                sample[i][j] = 'a'
+
+    moves = [['.' for _ in range(len(sample[0]))] for _ in range(len(sample))]
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            moves[i][j] = direction(sample, i, j)
+
+    # Chaque 'a' est maintenant un point de départ
+    heights = [[-1 for _ in range(len(sample[0]))] for _ in range(len(sample))]
+    for i in range(len(sample)):
+        for j in range(len(sample[0])):
+            if sample[i][j] == 'a':
+                heights[i][j] = 0
+    
+
+    steps = 0
+    changed = True
+    while heights[end[0]][end[1]] == -1 and changed:
+        steps += 1
+        heights, changed = update_heights(moves, heights, sample)
+
+        #print_val(sample, heights)
+
+    return heights[end[0]][end[1]]
+
+
+def main():
+    """Fonction principale"""
+    print(f"part1: {part1(read_sample())}")
+    print(f"part2: {part2(read_sample())}")
+
+if __name__ == "__main__":
+    main()
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