Initial commit

2024/20/README.md

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+Reading comprehension got me on the second part,
+a one byte change helped 🙃

2024/20/demog

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+#####
+#S#E#
+#...#
+#####

2024/20/demog2

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+#############################################################################################
+#S#........................................................................................E#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#.#########################################################################################.#
+#...........................................................................................#
+#############################################################################################

2024/20/demog3

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+######
+#...E#
+#S####
+#....#
+######

2024/20/one.py

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+#!/usr/bin/env python3
+
+import collections
+import sys
+
+input_file = sys.argv[1]
+
+with open(input_file) as fd:
+    lines = [line.rstrip() for line in fd.readlines()]
+
+height = len(lines)
+width = len(lines[0])
+
+vec = tuple[int, int]
+directions = [
+    (-1, 0),  # ^ North
+    (0, 1),  # > East
+    (1, 0),  # v South
+    (0, -1),  # < West
+]
+
+Cheat = tuple[vec, int]
+
+cheats: set[Cheat] = set()
+for i, line in enumerate(lines):
+    if "S" in line:
+        j = line.index("S")
+        start = i, j
+    if i in range(1, height - 1):
+        for j in range(1, width - 1):
+            char = lines[i][j]
+            if char != "#":
+                continue
+            for d, direction in enumerate(directions):
+                ii, jj = i + direction[0], j + direction[1]
+                if ii not in range(1, height - 1) or jj not in range(1, width - 1):
+                    continue
+                cchar = lines[ii][jj]
+                if cchar == "#":
+                    continue
+                cheats.add(((i, j), d))
+
+
+def print_grid(visited: list[list[int | None]], cheat: Cheat) -> None:
+    for i in range(height):
+        line = ""
+        for j in range(width):
+            char = lines[i][j]
+            if visited[i][j] is not None:
+                char = "O"
+            if cheat[0] == (i, j):
+                char = "X"
+            line += char
+        print(line)
+    print()
+
+
+def time(cheat: Cheat) -> int | None:
+    visited: list[list[int | None]] = list()
+    for _ in range(height):
+        visited.append([None] * width)
+    stack: set[vec] = {start}
+    for s in range(1, 10000):
+        nstack: set[vec] = set()
+        for pos in stack:
+            i, j = pos
+            for d, direction in enumerate(directions):
+                if (i, j) == cheat[0]:
+                    if d != cheat[1]:
+                        continue
+                ii, jj = i + direction[0], j + direction[1]
+                cchar = lines[ii][jj]
+                if cchar == "#" and cheat != ((ii, jj), d):
+                    continue
+                elif cchar == "E":
+                    # if s == 84 - 8:
+                    #     print_grid(visited, cheat)
+                    return s
+                previs = visited[ii][jj]
+                if previs is not None and previs < s:
+                    continue
+                visited[ii][jj] = s
+                nstack.add((ii, jj))
+        stack = nstack
+
+        # print("Second", s)
+        # print_grid(visited)
+    else:
+        return None
+
+
+canon_saves: collections.Counter[int] = collections.Counter()
+for k, v in (
+    {
+        2: 14,
+        4: 14,
+        6: 2,
+        8: 4,
+        10: 2,
+        12: 3,
+        20: 1,
+        36: 1,
+        38: 1,
+        40: 1,
+        64: 1,
+    }
+).items():
+    canon_saves[k] = v
+
+normal = time(((0, 0), 0))
+assert normal
+saves: collections.Counter[int] = collections.Counter()
+saves_mo100 = 0
+print(f"{normal=}")
+print(f"{len(cheats)=}")
+for c, cheat in enumerate(cheats):
+    print("Cheat", c, "/", len(cheats))
+    ntime = time(cheat)
+    assert ntime
+    diff = normal - ntime
+    saves[diff] += 1
+    if diff >= 100:
+        saves_mo100 += 1
+del saves[0]
+print(f"{saves=}")
+print(f"{canon_saves=}")
+print(f"{(saves == canon_saves)=}")
+print(saves_mo100)
+# 1282: too low

2024/20/reddit_part3

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+#########################################
+#...#.............#.....#.....#.....#...#
+###.#.###.#########.###.###.#####.###.#.#
+#...#...#.#.#.....#...#...#.#.........#.#
+#..##.###.#.#####.#####.#.#.#.#####.#.#.#
+#.......#.....#.#.....#.#...#...#...#.#.#
+#.###########.#.#.####.####.#.###########
+#.#.#...#...#.....#.................#...#
+#.#.#.#.#.#.###.#.#.###.#########.#####.#
+#.....#...#.....#...#.........#...#.#.#.#
+#####.#####.#####.#.#.#.#.#######.#.#.#.#
+#.....#.........#.#.#...#...#...#.#...#.#
+#.#########.#######.#####.#.##..###.###.#
+#...#.......#.....#.#...#.#...#.....#...#
+#.###.###########.#.###.#.#.###.#######.#
+#.#.#.............#.....#.#...#...#.....#
+###.#.#####.#####.#.###.#.#####.#####.###
+#...#.#.........#.#...#...#...#.#.....#.#
+###.###.#.#########.#####.###.#.#.#.#.#.#
+#S#.#...#.#.....#.....#.........#.#.#..E#
+#.#.#.#########.#.#########.#.###.#####.#
+#.....#.........#...#.#...#.#.....#...#.#
+###.#####..##.#.#####.#.###.#####.###.###
+#.#.#...#.#.#.#.#...#...#...#.........#.#
+#.#.###.###.#.#.#.#####.####.##.#.#####.#
+#.#.#.#.#.#...#.........#.#...#.#.#...#.#
+#.#.#.#.#.#####.###.#.#.#.###.#.###.###.#
+#...#.......#...#...#.#.#.........#.#...#
+#######.#####.#####.###.#.#.#####.#.###.#
+#.............#.....#.#.#.#.....#.......#
+###############.#####.#.#########.#.#.###
+#.....#...#.#.........#.#...#...#.#.#.#.#
+#.#.#.#.#.#.###.#########.###.###.#####.#
+#.#.#.#.#...........#.#.............#...#
+###.#.#.###.#######.#.#.#.###.###.#.#.###
+#...#...#...#.#...#.#...#...#.#.#.#.#...#
+###.#.#######.#.#.#.###.#####.#..##.#.###
+#.#.#...#.....#.#.#.......#.#.#...#.....#
+#.#.#####.###.#.#.#.#.#####.#####.###.#.#
+#.....#.....#.......#.............#...#.#
+#########################################

2024/20/reddit_part3g

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+#########################################
+#...#.............#.....#.....#.....#...#
+###.#.###.#########.###.###.#####.###.#.#
+#...#...#.#.#.....#...#...#.#.........#.#
+#..##.###.#.#####.#####.#.#.#.#####.#.#.#
+#.......#.....#.#.....#.#...#...#...#.#.#
+#.###########.#.#.####.####.#.###########
+#.#.#...#...#.....#.................#...#
+#.#.#.#.#.#.###.#.#.###.#########.#####.#
+#.....#...#.....#...#.........#...#.#.#.#
+#####.#####.#####.#.#.#.#.#######.#.#.#.#
+#.....#.........#.#.#...#...#...#.#...#.#
+#.#########.#######.#####.#.##..###.###.#
+#...#.......#.....#.#...#.#...#.....#...#
+#.###.###########.#.###.#.#.###.#######.#
+#.#.#.............#.....#.#...#...#.....#
+###.#.#####.#####.#.###.#.#####.#####.###
+#...#.#.........#.#...#...#...#.#.....#.#
+###.###.#.#########.#####.###.#.#.#.#.#.#
+#S#.#...#.#.....#.....#.........#.#.#..E#
+#.#.#.#########.#.#########.#.###.#####.#
+#.....#.........#...#.#...#.#.....#...#.#
+###.#####..##.#.#####.#.###.#####.###.###
+#.#.#...#.#.#.#.#...#...#...#.........#.#
+#.#.###.###.#.#.#.#####.####.##.#.#####.#
+#.#.#.#.#.#...#.........#.#...#.#.#...#.#
+#.#.#.#.#.#####.###.#.#.#.###.#.###.###.#
+#...#.......#...#...#.#.#.........#.#...#
+#######.#####.#####.###.#.#.#####.#.###.#
+#.............#.....#.#.#.#.....#.......#
+#####################.#.#########.#.#.###
+#.....#...#.#.........#.#...#...#.#.#.#.#
+#.#.#.#.#.#.###.#########.###.###.#####.#
+#.#.#.#.#...........#.#.............#...#
+###.#.#.###.#######.#.#.#.###.###.#.#.###
+#...#...#...#.#...#.#...#...#.#.#.#.#...#
+###.#.#######.#.#.#.###.#####.#..##.#.###
+#.#.#...#.....#.#.#.......#.#.#...#.....#
+#.#.#####.###.#.#.#.#.#####.#####.###.#.#
+#.....#.....#.......#.............#...#.#
+#########################################

2024/20/two.py

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+#!/usr/bin/env python3
+
+import collections
+import sys
+
+input_file = sys.argv[1]
+
+with open(input_file) as fd:
+    lines = [line.rstrip() for line in fd.readlines()]
+
+height = len(lines)
+width = len(lines[0])
+
+# Adjust parameters for part/file
+part = int(sys.argv[2])
+assert part in (1, 2)
+
+if input_file.startswith("input"):
+    minic = 100
+else:
+    if part == 1:
+        minic = 1
+    else:
+        minic = 50
+skips = 1 if part == 1 else 20
+canon: collections.Counter[int] = collections.Counter()
+demo = {}
+if input_file == "demo":
+    if skips == 1:
+        demo = {2: 14, 4: 14, 6: 2, 8: 4, 10: 2} | (
+            {12: 3, 20: 1, 36: 1, 38: 1, 40: 1, 64: 1}
+        )
+    elif skips == 20:
+        demo = {50: 32, 52: 31, 54: 29, 56: 39, 58: 25, 60: 23} | (
+            {62: 20, 64: 19, 66: 12, 68: 14, 70: 12, 72: 22, 74: 4, 76: 3}
+        )
+    for k, v in demo.items():
+        canon[k] = v
+
+vec = tuple[int, int]
+directions = [
+    (-1, 0),  # ^ North
+    (0, 1),  # > East
+    (1, 0),  # v South
+    (0, -1),  # < West
+]
+
+# Find start position
+for i, line in enumerate(lines):
+    if "S" in line:
+        j = line.index("S")
+        start = i, j
+
+
+# Visit normally
+normal = None
+visited: list[list[int | None]] = list()
+for _ in range(height):
+    visited.append([None] * width)
+visited[start[0]][start[1]] = 0
+stack: set[vec] = {start}
+s = 0
+while stack:
+    s += 1
+    nstack: set[vec] = set()
+    for pos in stack:
+        i, j = pos
+        for d, direction in enumerate(directions):
+            ii, jj = i + direction[0], j + direction[1]
+
+            previs = visited[ii][jj]
+            if previs is not None and previs < s:
+                continue
+            visited[ii][jj] = s
+
+            cchar = lines[ii][jj]
+            if cchar == "#":
+                continue
+            elif cchar == "E":
+                if normal is None:
+                    normal = s
+            nstack.add((ii, jj))
+    stack = nstack
+assert normal
+
+# Print
+for i in range(height):
+    line = ""
+    for j in range(width):
+        char = lines[i][j]
+        if visited[i][j] is not None:
+            if char == "#":
+                char = "@"
+            else:
+                char = "O"
+        line += char
+    print(line)
+print()
+
+
+# Find cheats
+saves: collections.Counter[int] = collections.Counter()
+for i in range(1, height - 1):
+    if height > 100:
+        print(103, i, "/", height)
+    for j in range(1, width - 1):
+        char = lines[i][j]
+        if char == "#":
+            continue
+        ovis = visited[i][j]
+        if ovis is None:
+            continue
+        if ovis >= normal:
+            continue
+        # for di in range(-skips, skips):
+        #     ii = i + di
+        #     G
+        for ii in range(1, height - 1):
+            for jj in range(1, width - 1):
+                manh = abs(i - ii) + abs(j - jj)
+                if manh > skips:
+                    continue
+                cchar = lines[ii][jj]
+                if cchar == "#":
+                    continue
+                nvis = visited[ii][jj]
+                if nvis is None:
+                    continue
+                orem = normal - ovis
+                nrem = abs(normal - nvis) + manh
+                save = orem - nrem
+                if save < minic:
+                    continue
+                saves[save] += 1
+
+
+print(f"{normal=}")
+print(f"{dict(sorted(saves.items()))=}")
+if demo:
+    print(f"{dict(sorted(canon.items()))=}")
+    diff = canon.copy()
+    diff.subtract(saves)
+    print(f"{dict(sorted(diff.items()))=}")
+    print(f"{(saves == canon)=}")
+    print(f"{saves.total()=}")
+    print(f"{canon.total()=}")
+    difft = 0
+    for v in diff.values():
+        difft += abs(v)
+    print(f"{difft=}")
+print(saves.total())
+# 1119834 too high
+# 982425 correct!

2024/20/two_correct.py

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+#!/usr/bin/env python3
+
+import collections
+import colorsys
+import sys
+
+import rich.console
+
+import rich.text
+import rich.progress
+
+console = rich.console.Console()
+
+input_file = sys.argv[1]
+
+with open(input_file) as fd:
+    lines = [line.rstrip() for line in fd.readlines()]
+
+height = len(lines)
+width = len(lines[0])
+
+# Adjust parameters for part/file
+part = int(sys.argv[2])
+assert part in (1, 2)
+
+if input_file.startswith("input"):
+    minic = 100
+elif input_file.startswith("reddit_part3"):
+    minic = 30
+else:
+    if part == 1:
+        minic = 1
+    else:
+        minic = 50
+skips = 2 if part == 1 else 20
+canon: collections.Counter[int] = collections.Counter()
+demo = {}
+if input_file == "demo":
+    if part == 1:
+        demo = {2: 14, 4: 14, 6: 2, 8: 4, 10: 2} | (
+            {12: 3, 20: 1, 36: 1, 38: 1, 40: 1, 64: 1}
+        )
+    elif part == 2:
+        demo = {50: 32, 52: 31, 54: 29, 56: 39, 58: 25, 60: 23} | (
+            {62: 20, 64: 19, 66: 12, 68: 14, 70: 12, 72: 22, 74: 4, 76: 3}
+        )
+    for k, v in demo.items():
+        canon[k] = v
+
+vec = tuple[int, int]
+directions = [
+    (-1, 0),  # ^ North
+    (0, 1),  # > East
+    (1, 0),  # v South
+    (0, -1),  # < West
+]
+
+# Find start position
+for i, line in enumerate(lines):
+    if "S" in line:
+        j = line.index("S")
+        start = i, j
+    if "E" in line:
+        j = line.index("E")
+        stop = i, j
+
+
+# Visit forward
+normal = None
+forward: list[list[int | None]] = list()
+for _ in range(height):
+    forward.append([None] * width)
+forward[start[0]][start[1]] = 0
+stack: set[vec] = {start}
+s = 0
+while stack:
+    s += 1
+    nstack: set[vec] = set()
+    for pos in stack:
+        i, j = pos
+        for d, direction in enumerate(directions):
+            ii, jj = i + direction[0], j + direction[1]
+
+            cchar = lines[ii][jj]
+            if cchar == "#":
+                continue
+
+            previs = forward[ii][jj]
+            if previs is not None and previs < s:
+                continue
+            forward[ii][jj] = s
+
+            if cchar == "E":
+                if normal is None:
+                    normal = s
+            nstack.add((ii, jj))
+    stack = nstack
+assert normal
+
+# Visit backwards
+backward: list[list[int | None]] = list()
+for _ in range(height):
+    backward.append([None] * width)
+backward[stop[0]][stop[1]] = 0
+stack = {stop}
+s = 0
+while stack:
+    s += 1
+    nstack = set()
+    for pos in stack:
+        i, j = pos
+        for d, direction in enumerate(directions):
+            ii, jj = i + direction[0], j + direction[1]
+
+            cchar = lines[ii][jj]
+            if cchar == "#":
+                continue
+
+            previs = backward[ii][jj]
+            if previs is not None and previs < s:
+                continue
+            backward[ii][jj] = s
+
+            if cchar == "E":
+                assert s == normal
+            nstack.add((ii, jj))
+    stack = nstack
+
+# Print
+
+
+def perc2color(perc: float) -> str:
+    rgb = colorsys.hsv_to_rgb(perc, 1.0, 1.0)
+    r, g, b = tuple(round(c * 255) for c in rgb)
+    return f"rgb({r},{g},{b})"
+
+
+text = rich.text.Text()
+for i in range(height):
+    for j in range(width):
+        fg = "white"
+        bg = "black"
+        char = lines[i][j]
+        forw = forward[i][j]
+        if char == ".":
+            if forw is not None:
+                fg = perc2color(forw / normal)
+                char = str(forw % 10)
+            bckw = backward[i][j]
+            if bckw is not None:
+                bg = perc2color(bckw / normal)
+        if char == "#":
+            char = "█"
+        text.append(char, style=f"{fg} on {bg}")
+    text.append("\n")
+console.print(text)
+
+
+# Find cheats
+saves: collections.Counter[int] = collections.Counter()
+for i in rich.progress.track(range(1, height - 1), description="Finding cheats"):
+    for j in range(1, width - 1):
+        char = lines[i][j]
+        if char == "#":
+            continue
+        ovis = forward[i][j]
+        if ovis is None:
+            continue
+        if ovis >= normal:
+            continue
+        min_i = max(1, i - skips)
+        max_i = min(height - 1, i + skips)
+        for ii in range(min_i, max_i + 1):
+            rem = skips - abs(ii - i)
+            min_j = max(1, j - rem)
+            max_j = min(width - 1, j + rem)
+            for jj in range(min_j, max_j + 1):
+                manh = abs(i - ii) + abs(j - jj)
+                if manh > skips:
+                    continue
+                cchar = lines[ii][jj]
+                if cchar == "#":
+                    continue
+                nvis = backward[ii][jj]
+                if nvis is None:
+                    continue
+                orem = normal - ovis
+                nrem = nvis + manh
+                save = orem - nrem
+                if save < minic:
+                    continue
+                saves[save] += 1
+
+log = console.log
+
+log(f"{normal=}")
+log(f"{dict(sorted(saves.items()))=}")
+if demo:
+    log(f"{dict(sorted(canon.items()))=}")
+    diff = canon.copy()
+    diff.subtract(saves)
+    log(f"{dict(sorted(diff.items()))=}")
+    log(f"{(saves == canon)=}")
+    log(f"{saves.total()=}")
+    log(f"{canon.total()=}")
+    difft = 0
+    for v in diff.values():
+        difft += abs(v)
+    log(f"{difft=}")
+print(saves.total())
+# 1119834 too high
+# 982425 correct!

2024/20/two_fast.py

@@ -0,0 +1,172 @@
+#!/usr/bin/env python3
+
+import collections
+import colorsys
+import sys
+import rich.console
+
+console = rich.console.Console()
+
+input_file = sys.argv[1]
+
+with open(input_file) as fd:
+    lines = [line.rstrip() for line in fd.readlines()]
+
+height = len(lines)
+width = len(lines[0])
+
+# Adjust parameters for part/file
+part = int(sys.argv[2])
+assert part in (1, 2)
+
+if input_file.startswith("input"):
+    minic = 100
+elif input_file.startswith("reddit_part3"):
+    minic = 30
+else:
+    if part == 1:
+        minic = 1
+    else:
+        minic = 50
+skips = 2 if part == 1 else 20
+canon: collections.Counter[int] = collections.Counter()
+demo = {}
+if input_file == "demo":
+    if part == 1:
+        demo = {2: 14, 4: 14, 6: 2, 8: 4, 10: 2} | (
+            {12: 3, 20: 1, 36: 1, 38: 1, 40: 1, 64: 1}
+        )
+    elif part == 2:
+        demo = {50: 32, 52: 31, 54: 29, 56: 39, 58: 25, 60: 23} | (
+            {62: 20, 64: 19, 66: 12, 68: 14, 70: 12, 72: 22, 74: 4, 76: 3}
+        )
+    for k, v in demo.items():
+        canon[k] = v
+
+vec = tuple[int, int]
+directions = [
+    (-1, 0),  # ^ North
+    (0, 1),  # > East
+    (1, 0),  # v South
+    (0, -1),  # < West
+]
+
+# Find start position
+for i, line in enumerate(lines):
+    if "S" in line:
+        j = line.index("S")
+        start = i, j
+
+
+# Visit normally
+normal = None
+visited: list[list[int | None]] = list()
+for _ in range(height):
+    visited.append([None] * width)
+visited[start[0]][start[1]] = 0
+stack: set[vec] = {start}
+s = 0
+while stack:
+    s += 1
+    nstack: set[vec] = set()
+    for pos in stack:
+        i, j = pos
+        for d, direction in enumerate(directions):
+            ii, jj = i + direction[0], j + direction[1]
+
+            cchar = lines[ii][jj]
+            if cchar == "#":
+                continue
+
+            previs = visited[ii][jj]
+            if previs is not None and previs < s:
+                continue
+            visited[ii][jj] = s
+
+            if cchar == "E":
+                if normal is None:
+                    normal = s
+            nstack.add((ii, jj))
+    stack = nstack
+assert normal
+
+# Print
+for i in range(height):
+    line = ""
+    for j in range(width):
+        char = lines[i][j]
+        vis = visited[i][j]
+        if (i, j) == (19, 1):
+            char = "[bold red on black]@"
+        elif (i, j) == (15, 1):
+            char = "[bold red on black]a"
+        elif vis is not None and char == ".":
+            hue = vis / normal
+            rgb = colorsys.hsv_to_rgb(hue, 1.0, 1.0)
+            r, g, b = tuple(round(c * 255) for c in rgb)
+            char = f"[on rgb({r},{g},{b})]{vis % 10}"
+        elif char == "#":
+            char = "[white]█"
+        else:
+            char = f"[bold green on black]{char}"
+        line += char
+    console.print(line)
+print()
+
+
+# Find cheats
+saves: collections.Counter[int] = collections.Counter()
+for i in range(1, height - 1):
+    if height > 100:
+        print(103, i, "/", height-2)
+    for j in range(1, width - 1):
+        char = lines[i][j]
+        if char == "#":
+            continue
+        ovis = visited[i][j]
+        if ovis is None:
+            continue
+        if ovis >= normal:
+            continue
+        min_i = max(1, i-skips)
+        max_i = min(height-1, i+skips)
+        for ii in range(min_i, max_i+1):
+            rem = skips - abs(ii - i)
+            min_j = max(1, j-rem)
+            max_j = min(width-1, j+rem)
+            for jj in range(min_j, max_j+1):
+                manh = abs(i - ii) + abs(j - jj)
+                if manh > skips:
+                    continue
+                cchar = lines[ii][jj]
+                if cchar == "#":
+                    continue
+                nvis = visited[ii][jj]
+                if nvis is None:
+                    continue
+                orem = normal - ovis
+                # Works if there's space after the E, but catches unrelated paths
+                nrem = abs(normal - nvis) + manh
+                save = orem - nrem
+                if save < minic:
+                    continue
+                saves[save] += 1
+
+
+print(f"{normal=}")
+print(f"{dict(sorted(saves.items()))=}")
+if demo:
+    print(f"{dict(sorted(canon.items()))=}")
+    diff = canon.copy()
+    diff.subtract(saves)
+    print(f"{dict(sorted(diff.items()))=}")
+    print(f"{(saves == canon)=}")
+    print(f"{saves.total()=}")
+    print(f"{canon.total()=}")
+    difft = 0
+    for v in diff.values():
+        difft += abs(v)
+    print(f"{difft=}")
+print(saves.total())
+# 1119834 too high
+# 982425 correct!