From bc91ad5dadd85ecb5338deab5708fdc3eeda4a5d Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Sun, 25 Dec 2022 11:24:28 +0100
Subject: [PATCH] 2022: d25: ex1: add solution

---
 2022/d25/ex1/ex1.py | 50 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100755 2022/d25/ex1/ex1.py

diff --git a/2022/d25/ex1/ex1.py b/2022/d25/ex1/ex1.py
new file mode 100755
index 0000000..59686b9
--- /dev/null
+++ b/2022/d25/ex1/ex1.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+
+import sys
+
+
+def solve(input: list[str]) -> str:
+    def from_snafu(input: str) -> int:
+        res = 0
+        for c in input:
+            if c == "=":
+                n = -2
+            elif c == "-":
+                n = -1
+            else:
+                n = int(c)
+            res = res * 5 + n
+        return res
+
+    def to_snafu(input: int) -> str:
+        # Base case
+        if not input:
+            return "0"
+
+        DIGITS = {
+            2: "2",
+            1: "1",
+            0: "0",
+            -1: "-",
+            -2: "=",
+        }
+
+        digits: list[int] = []
+        while input:
+            input, d = divmod(input, 5)
+            if d not in DIGITS:
+                d -= 5
+                input += 1
+            digits.append(d)
+        return "".join(DIGITS[c] for c in reversed(digits))
+
+    return to_snafu(sum(map(from_snafu, input)))
+
+
+def main() -> None:
+    input = sys.stdin.read().splitlines()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()