From f651907e86eb2404d872b7cd61382db5e4f4d2d2 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Fri, 9 May 2025 16:06:37 +0100
Subject: [PATCH] 2017: d03: ex1: add solution

---
 2017/d03/ex1/ex1.py | 46 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100755 2017/d03/ex1/ex1.py

diff --git a/2017/d03/ex1/ex1.py b/2017/d03/ex1/ex1.py
new file mode 100755
index 0000000..64f7dbb
--- /dev/null
+++ b/2017/d03/ex1/ex1.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+
+import itertools
+import sys
+from typing import NamedTuple
+
+
+class Point(NamedTuple):
+    x: int
+    y: int
+
+
+def solve(input: str) -> int:
+    def target_coord(target: int) -> Point:
+        for dist in itertools.count():
+            side = dist * 2 + 1
+            bot_right = side * side
+            if bot_right < target:
+                continue
+            # Target must be in the last loop, before bot_right
+            bot_left = bot_right - side + 1
+            top_left = bot_left - side + 1
+            top_right = top_left - side + 1
+            if bot_left <= target <= bot_right:
+                return Point(dist - (bot_right - target), -dist)
+            if top_left <= target <= bot_left:
+                return Point(-dist, -dist + (bot_left - target))
+            if top_right <= target <= top_left:
+                return Point(-dist + (top_left - target), dist)
+            if target <= top_right:
+                return Point(dist, dist - (top_right - target))
+            assert False  # Sanity check
+        assert False  # Sanity check
+
+    target = int(input)
+    coord = target_coord(target)
+    return abs(coord.x) + abs(coord.y)
+
+
+def main() -> None:
+    input = sys.stdin.read()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()