Solution 1

Author: Jacob Summerville

rounds/1_histogram/solution.py

@@ -1,14 +1,43 @@
 """Your Round 1 solution — byte-pair histogram.
 
-**Edit this file.** It currently delegates to ``baseline.py`` so everything
-passes out of the box. Replace the body of ``compute_histogram`` with your
-own faster implementation.
+This version keeps the same contract as ``baseline.py`` but replaces the
+per-bigram Python loop with NumPy operations over the whole byte buffer.
 """
 
+from __future__ import annotations
+from pathlib import Path
+
+import numpy as np
+
+DATA_DIR = Path(__file__).parent / "data"
+FIXTURE_PATH = DATA_DIR / "fixture_payload.bin"
+
 
 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)
+    # Read the whole file into memory as a single bytes object
+    with open(path, 'rb') as f:
+        data = f.read()
+
+    # Expose the bytes object as a uint8 NumPy array without copying
+    byte_values = np.frombuffer(data, dtype=np.uint8)
+
+    # Encode each overlapping 2-byte window as a uint16 token
+    bigrams = byte_values[:-1].astype(np.uint16)
+    bigrams <<= 8
+    bigrams |= byte_values[1:]
+
+    # Count the uint16 tokens directly
+    counts = np.bincount(bigrams, minlength=1 << 16)
+
+    # Convert back into the return format
+    return {
+        int(token).to_bytes(2, "big"): int(count)
+        for token, count in enumerate(counts)
+        if count
+    }
+
+
+if __name__ == '__main__':
+    compute_histogram(str(FIXTURE_PATH))