reorganise directories

upd chapter_01/binary.py

chapter_01/README.md

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+# Binary Search
+
+Repeatedly split the array checking if value is greater or less than the mid point. Stop when the exact value is found.
+
+It takes log N steps to reduce an array of size N to an array of size 1. Time complexity for this algorithm is `O(log N)`.

chapter_01/binary.py

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+import logging
+import random
+
+logging.basicConfig(level=logging.DEBUG)
+logger = logging.getLogger(__name__)
+
+
+class BinarySearch:
+    def __init__(self, arr):
+        self._arr = arr
+
+    def search(self, item):
+        low = 0
+        high = len(self._arr) - 1
+
+        while low <= high:
+            mid = (low + high) // 2
+            guess = self._arr[mid]
+            if guess == item:
+                return mid
+            elif guess > item:
+                high = mid - 1
+            else:
+                low = mid + 1
+
+        return None
+
+
+LOWER = 1000
+UPPER = 1000000
+SAMPLE_SIZE = 1000
+
+
+numbers = random.sample(range(LOWER, UPPER), SAMPLE_SIZE)
+numbers.extend([9000, 999999])
+numbers.sort()
+print(numbers)
+
+search = BinarySearch(numbers)
+print(search.search(42))
+print(search.search(9000))
+print(search.search(20000))
+print(search.search(60000))
+print(search.search(999999))