Fix coordinate compression bug

DIRECTORY.md

@@ -173,6 +173,8 @@
   * [Volume Conversions](conversions/volume_conversions.py)
   * [Weight Conversion](conversions/weight_conversion.py)
 
+## [Coordinate Compression](/coordinate_compression.py)
+
 ## Data Compression
   * [Burrows Wheeler](data_compression/burrows_wheeler.py)
   * [Coordinate Compression](data_compression/coordinate_compression.py)
@@ -1243,6 +1245,7 @@
 
 ## Searches
   * [Binary Search](searches/binary_search.py)
+  * [Binary Search With Duplicates](searches/binary_search_with_duplicates.py)
   * [Binary Tree Traversal](searches/binary_tree_traversal.py)
   * [Double Linear Search](searches/double_linear_search.py)
   * [Double Linear Search Recursion](searches/double_linear_search_recursion.py)

coordinate_compression.py

@@ -0,0 +1,10 @@
+def compress(value):
+    if value not in coordinate_map:
+        raise ValueError(f"{value} not found in coordinate map")
+    return coordinate_map[value]
+
+
+def decompress(index):
+    if index < 0 or index >= len(original_values):
+        raise ValueError(f"Index {index} is out of bounds")
+    return original_values[index]

searches/binary_search_with_duplicates.py

@@ -0,0 +1,21 @@
+def binary_search_first_occurrence(arr: list[int], target: int) -> int:
+    """
+    Return the index of the first occurrence of target in a sorted list.
+
+    >>> binary_search_first_occurrence([1, 2, 4, 4, 4, 5], 4)
+    2
+    >>> binary_search_first_occurrence([1, 2, 3], 5)
+    -1
+    """
+    left, right = 0, len(arr) - 1
+    result = -1
+    while left <= right:
+        mid = (left + right) // 2
+        if arr[mid] == target:
+            result = mid
+            right = mid - 1
+        elif arr[mid] < target:
+            left = mid + 1
+        else:
+            right = mid - 1
+    return result