Fix file

Author: stefmolin

rounds/1_histogram/baseline.py

@@ -4,13 +4,21 @@
 tokens) in a binary payload.
 """
 
-from collections import Counter
-from itertools import pairwise
-
 
 def compute_histogram(path: str) -> dict[bytes, int]:
     """Frequency of every 2-byte bigram in the file at ``path``."""
+    # Step 1: read the whole file into memory as a single bytes object.
     with open(path, "rb") as f:
         data = f.read()
 
-    return Counter(bytes(bigram) for bigram in pairwise(data))
+    # Step 2: slide a 2-byte window across the buffer. For ``b"ABCD"`` the
+    # iterations produce ``b"AB"``, ``b"BC"``, then ``b"CD"``. For each window,
+    # bump the matching bucket in a ``dict`` keyed by the bigram itself.
+    counts: dict[bytes, int] = {}
+    for i in range(len(data) - 1):
+        bigram = data[i : i + 2]
+        if bigram in counts:
+            counts[bigram] += 1
+        else:
+            counts[bigram] = 1
+    return counts

rounds/1_histogram/solution.py

@@ -5,10 +5,11 @@
 own faster implementation.
 """
 
+from collections import Counter
+from itertools import pairwise
+from pathlib import Path
+
 
 def compute_histogram(path: str) -> dict[bytes, int]:
     """Frequency of every 2-byte bigram in the file at ``path``."""
-    # TODO: remove this delegation and write your own implementation here.
-    from .baseline import compute_histogram as _baseline
-
-    return _baseline(path)
+    return Counter(bytes(bigram) for bigram in pairwise(Path(path).read_bytes()))