Days 7, 8, 9. 9 was fun.

README.md

@@ -6,4 +6,7 @@
 - Day 4: 7:08 but top 100 required 3:33 still okay
 - Day 5: 11:56 but 7:58 for top 100... getting better?
 - Day 6: 3:50 but 2:25 for leaderboard :D
-- Day 7: 
+- Day 7: 27:55 and 14:47 for leaderboard; okay, I would say
+- Day 8: 61:00 and 10:00 for leaderboard; I need template code for searching coordinate systems
+- Day 9: 58:00 and 7:32 for leaderboard; I need code for 2D stuff
+- Day 10:

d7.py

@@ -0,0 +1,117 @@
+import re
+from string import ascii_lowercase, ascii_uppercase, digits
+
+EXAMPLE = """
+$ cd /
+$ ls
+dir a
+14848514 b.txt
+8504156 c.dat
+dir d
+$ cd a
+$ ls
+dir e
+29116 f
+2557 g
+62596 h.lst
+$ cd e
+$ ls
+584 i
+$ cd ..
+$ cd ..
+$ cd d
+$ ls
+4060174 j
+8033020 d.log
+5626152 d.ext
+7214296 k
+"""
+
+def clean(text: str) -> list[str]:
+    return list(filter(lambda l: l.strip() != "", text.splitlines()))
+
+def solve(lines: list[str]):
+    sizes = {}
+    res = 0
+
+    current_dir = ()
+    for line in lines:
+        if line.startswith("$ cd"):
+            c = line.replace("$ cd ", "").strip()
+            if c == "..":
+                current_dir = tuple(list(current_dir)[:-1])
+            else:
+                current_dir = tuple(list(current_dir) + [c])
+        elif line[0] in digits:
+            size, _ = line.split()
+            size = int(size)
+            try:
+                sizes[current_dir] += size
+            except KeyError:
+                sizes[current_dir] = size
+
+            for i in range(1, len(current_dir)):
+                outer_dir = tuple(list(current_dir)[:-i])
+                try:
+                    sizes[outer_dir] += size
+                except KeyError:
+                    sizes[outer_dir] = size
+
+    for _, size in sizes.items():
+        if size <= 100000:
+            res += size
+    # 23:50
+    return res
+
+def solve2(lines: list[str]):
+    sizes = {}
+    res = 0
+
+    current_dir = ()
+    for line in lines:
+        if line.startswith("$ cd"):
+            c = line.replace("$ cd ", "").strip()
+            if c == "..":
+                current_dir = tuple(list(current_dir)[:-1])
+            else:
+                current_dir = tuple(list(current_dir) + [c])
+        elif line[0] in digits:
+            size, _ = line.split()
+            size = int(size)
+            try:
+                sizes[current_dir] += size
+            except KeyError:
+                sizes[current_dir] = size
+
+            for i in range(1, len(current_dir)):
+                outer_dir = tuple(list(current_dir)[:-i])
+                try:
+                    sizes[outer_dir] += size
+                except KeyError:
+                    sizes[outer_dir] = size
+    total_space = 70000000
+    unused_space = 30000000
+    used_space = sizes[("/",)]
+
+    res = 2**32
+    for _, size in sizes.items():
+        if total_space - used_space + size >= unused_space and size < res:
+            res = size
+    # 27:55
+    return res
+
+def main():
+    example = clean(EXAMPLE)
+    print("Example  1:", solve(example))
+
+    data = clean(open("i7.txt").read())
+    print("Solution 1:", solve(data))
+
+    example = clean(EXAMPLE)
+    print("Example  2:", solve2(example))
+
+    data = clean(open("i7.txt").read())
+    print("Solution 2:", solve2(data))
+
+if __name__ == "__main__":
+    main()

d8.py

@@ -0,0 +1,132 @@
+import re
+from string import ascii_lowercase, ascii_uppercase
+
+EXAMPLE = """
+30373
+25512
+65332
+33549
+35390
+"""
+
+def clean(text: str) -> list[str]:
+    return list(filter(lambda l: l.strip() != "", text.splitlines()))
+
+
+def is_visible(trees, y_tree, x_tree):
+    y_max = len(trees)
+    x_max = len(trees[0])
+    tree_height = trees[y_tree][x_tree]
+
+    for x in range(0, x_tree):
+        if trees[y_tree][x] >= tree_height:
+            break
+    else:
+        return True
+
+    for x in range(x_tree + 1, x_max):
+        if trees[y_tree][x] >= tree_height:
+            break
+    else:
+        return True
+
+    for y in range(0, y_tree):
+        if trees[y][x_tree] >= tree_height:
+            break
+    else:
+        return True
+
+    for y in range(y_tree + 1, y_max):
+        if trees[y][x_tree] >= tree_height:
+            break
+    else:
+        return True
+    return False
+
+def solve(lines: list[str]):
+    res = 0
+    trees = []
+    for i in range(len(lines)):
+        line = lines[i]
+        trees.append(list(map(int, line)))
+
+    for y in range(len(trees)):
+        for x in range(len(trees)):
+            if is_visible(trees, y, x):
+                res += 1
+            else:
+                pass
+    return res
+
+
+def scenic_score(trees, y_tree, x_tree):
+    y_max = len(trees)
+    x_max = len(trees[0])
+
+    if x_tree == 0 or y_tree == 0 or x_tree == x_max - 1 or y_tree == y_max - 1:
+        return 0
+
+    tree_height = trees[y_tree][x_tree]
+    left, right, up, down = 0, 0, 0, 0
+
+    for x in range(x_tree - 1, -1, -1):
+        if trees[y_tree][x] < tree_height:
+            left += 1
+        else:
+            left += 1
+            break
+
+    for x in range(x_tree + 1, x_max):
+        if trees[y_tree][x] < tree_height:
+            right += 1
+        else:
+            right += 1
+            break
+
+    for y in range(y_tree - 1, -1, -1):
+        if trees[y][x_tree] < tree_height:
+            up += 1
+        else:
+            up += 1
+            break
+
+    for y in range(y_tree + 1, y_max):
+        if trees[y][x_tree] < tree_height:
+            down += 1
+        else:
+            down += 1
+            break
+
+    score = up * down * left * right
+    # print(f"{y_tree=} {x_tree=} {left=} {right=} {up=} {down=} {score=}")
+    return score
+
+def solve2(lines: list[str]):
+    trees = []
+    for i in range(len(lines)):
+        line = lines[i]
+        trees.append(list(map(int, line)))
+
+    max_score = 0
+    for y in range(len(trees)):
+        for x in range(len(trees)):
+            score = scenic_score(trees, y, x)
+            if score > max_score:
+                max_score = score
+    return max_score
+
+def main():
+    example = clean(EXAMPLE)
+    print("Example  1:", solve(example))
+
+    data = clean(open("i8.txt").read())
+    print("Solution 1:", solve(data))
+
+    example = clean(EXAMPLE)
+    print("Example  2:", solve2(example))
+
+    data = clean(open("i8.txt").read())
+    print("Solution 2:", solve2(data))
+
+if __name__ == "__main__":
+    main()

d9.py

@@ -0,0 +1,128 @@
+EXAMPLE = """
+R 4
+U 4
+L 3
+D 1
+R 4
+D 1
+L 5
+R 2
+"""
+
+def clean(text: str) -> list[str]:
+    return list(filter(lambda l: l.strip() != "", text.splitlines()))
+
+def new_pos(h_pos, t_pos, dir):
+    if dir == "R":
+        new_h_pos = (h_pos[0] + 1, h_pos[1])
+    elif dir == "U":
+        new_h_pos = (h_pos[0], h_pos[1] + 1)
+    elif dir == "L":
+        new_h_pos = (h_pos[0] - 1, h_pos[1])
+    elif dir == "D":
+        new_h_pos = (h_pos[0], h_pos[1] - 1)
+    elif dir == "NONE":
+        new_h_pos = (h_pos[0], h_pos[1])
+    else:
+        raise Exception("Unexpected direction.")
+
+    #  xxxxx
+    #  x---x     
+    #  x-O-x          
+    #  x---x   
+    #  xxxxx
+    dx, dy = t_pos[0] - new_h_pos[0], t_pos[1] - new_h_pos[1]
+    delta = {
+        (-1, -1): (0, 0),
+        (-1, 0): (0, 0),
+        (-1, 1): (0, 0),
+        (0, -1): (0, 0),
+        (0, 0): (0, 0),
+        (0, 1): (0, 0),
+        (1, -1): (0, 0),
+        (1, 0): (0, 0),
+        (1, 1): (0, 0),
+        (-2, 2): (1, -1),
+        (-2, 1): (1, -1),
+        (-2, 0): (1, 0),
+        (-2, -1): (1, 1),
+        (-2, -2): (1, 1),
+        (2, 2): (-1, -1),
+        (2, 1): (-1, -1),
+        (2, 0): (-1, 0),
+        (2, -1): (-1, 1),
+        (2, -2): (-1, 1),
+        (-1, 2): (1, -1),
+        (-1, -2): (1, 1),
+        (0, 2): (0, -1),
+        (0, -2): (0, 1),
+        (1, 2): (-1, -1),
+        (1, -2): (-1, 1),
+    }
+    dx_, dy_ = delta[(dx, dy)]
+    new_t_pos = t_pos[0] + dx_, t_pos[1] + dy_
+    # print(f"{h_pos=} {t_pos=} {dir=}")
+    # print(f"{new_h_pos=} {dx=} {dy=}")
+    # print(f"{new_t_pos=}")
+    # print("----")
+    return new_t_pos, new_h_pos
+
+def solve(lines: list[str]):
+    pos = set()
+    h_pos = (0, 0)
+    t_pos = (0, 0)
+    pos.add(t_pos)
+    for i in range(len(lines)):
+        dir, amount = lines[i].split()
+        for _ in range(int(amount)):
+            t_pos, h_pos = new_pos(h_pos, t_pos, dir)
+            pos.add(t_pos)
+    # 44:00
+    return len(pos)
+
+EXAMPLE2 = """
+R 5
+U 8
+L 8
+D 3
+R 17
+D 10
+L 25
+U 20
+"""
+
+def solve2(lines: list[str]):
+    vis = set()
+    poss = [(0, 0) for _ in range(10)]
+    vis.add((0, 0))
+    for i in range(len(lines)):
+        dir, amount = lines[i].split()
+        for _ in range(int(amount)):
+            for i in range(len(poss) - 1):
+                h_pos = poss[i]
+                t_pos = poss[i + 1]
+                if i == 0:
+                    t_pos, h_pos = new_pos(h_pos, t_pos, dir)
+                else:
+                    t_pos, h_pos = new_pos(h_pos, t_pos, "NONE")
+                poss[i] = h_pos
+                poss[i + 1] = t_pos
+            vis.add(poss[-1])
+    # 58:00
+    return len(vis)
+
+def main():
+    example = clean(EXAMPLE)
+    print("Example  1:", solve(example))
+
+    data = clean(open("i9.txt").read())
+    print("Solution 1:", solve(data))
+
+    example = clean(EXAMPLE2)
+    print("Example  2:", solve2(example))
+
+    data = clean(open("i9.txt").read())
+    print("Solution 2:", solve2(data))
+
+if __name__ == "__main__":
+    main()

dx.py

@@ -0,0 +1,39 @@
+import re
+from string import ascii_lowercase, ascii_uppercase
+
+EXAMPLE = """
+"""
+
+def clean(text: str) -> list[str]:
+    return list(filter(lambda l: l.strip() != "", text.splitlines()))
+
+def solve(lines: list[str]):
+    res = 0
+    for i, line in enumerate(lines):
+        print(i, line)
+    return res
+
+def solve2(lines: list[str]):
+    res = 0
+    for i, line in enumerate(lines):
+        print(i, line)
+    return res
+
+def main():
+    example = clean(EXAMPLE)
+    print("Example  1:", solve(example))
+    return
+
+    data = clean(open("i6.txt").read())
+    print("Solution 1:", solve(data))
+    return
+
+    example = clean(EXAMPLE)
+    print("Example  2:", solve2(example))
+    return
+
+    data = clean(open("i6.txt").read())
+    print("Solution 2:", solve2(data))
+
+if __name__ == "__main__":
+    main()