2023-01 (clean)

challenges/2023/01-trebuchet/main.py

@@ -1,5 +1,5 @@
 import sys
-from typing import Callable
+from typing import Optional
 
 
 def _debug(*args, **kwargs):
@@ -35,48 +35,38 @@ TRANSFORMATIONS = {
 }
 
 
-def collect_all_digits(line: str) -> list[str]:
-    res = []
-    for i, char in enumerate(line):
-        if char.isdigit():
-            res.append(char)
-            break
-        outer_break = False
-        for src in TRANSFORMATIONS:
-            if line[i : min(len(line), i + len(src))] == src:
-                res.append(TRANSFORMATIONS[src])
-                outer_break = True
-                break
-            if outer_break:
-                break
-
-    rev_line = "".join(reversed(line))
-
-    for i, char in enumerate(rev_line):
-        if char.isdigit():
-            res.append(char)
-            break
-        outer_break = False
-        for src in TRANSFORMATIONS:
-            if rev_line[i : min(len(line), i + len(src))] == "".join(reversed(src)):
-                res.append(TRANSFORMATIONS[src])
-                outer_break = True
-                break
-        if outer_break:
-            break
-
-    return res
+def find_first(inp: str, opts: list[str]) -> Optional[str]:
+    candidates = []
+    for opt in opts:
+        if (p := inp.find(opt)) != -1:
+            candidates.append((p, opt))
+    li = sorted(candidates, key=lambda x: x[0])
+    if len(li) == 0:
+        return None
+    return li[0][1]
 
 
 def two(inp: str):
     parsed = parse(inp)
     acc = 0
+
+    search_values = list(map(str, range(0, 10))) + list(TRANSFORMATIONS.keys())
+    reversed_search_values = ["".join(reversed(x)) for x in search_values]
+
     for line in parsed:
-        digits = collect_all_digits(line)
-        print(digits)
-        assert len(digits) != 0, f"must have at least one digit per line: {line}"
-        val = digits[0] + digits[-1]
+        first_digit = find_first(line, search_values)
+        second_digit = find_first("".join(reversed(line)), reversed_search_values)
+        assert first_digit is not None and second_digit is not None, f"must have at least one digit per line: {line}"
+
+        # second digit will be the reversed form
+        second_digit = "".join(reversed(second_digit))
+        
+        first_digit = TRANSFORMATIONS.get(first_digit, first_digit)
+        second_digit = TRANSFORMATIONS.get(second_digit, second_digit)
+
+        val = first_digit + second_digit
         acc += int(val)
+
     return acc