deliverable complete w review notes

search.py

@@ -19,3 +19,53 @@
 Output: 0
 Explanation: -1 exists in the list and its index is 0
 """
+
+
+# distance = high index - low index
+# middle index = low index + (distance // 2)
+
+def binary_search(nums, target):
+    # keep track of the window -- start by assuming the entire list is the window 
+    # vars for low index of the window, high index of the window, middle point index of the window
+    low = 0 
+    high = len(nums)
+    mid = high // 2
+
+    # account for case where target is first in the list
+    if target == nums[0]:
+        return 0 
+    # continously iterate until the target is found or we determine that the target cannot be found
+    while True:
+        # check the value at the midpoint against the target, stop iterating if target is found
+        if nums[mid] == target:
+            return mid
+        elif nums[mid] > target:
+            high = mid
+            difference = high - low
+            mid = low + (difference // 2)
+        # otherwise slide to the right
+        else:
+            low = mid
+            difference = high - low
+            mid = low + (difference // 2)
+
+        print(f"low: {low}, mid: {mid}, high: {high}")
+        # stop iteration when the midpoint is equal to low or high, because we did not find it 
+        # if mid <= low or mid >= high:
+        if low == mid:
+            return -1
+
+nums = [-1, 0, 3, 5, 9, 12]
+target = 9
+
+nums = [-1, 0, 3, 5, 9, 12]
+target = 2
+
+nums = [-1, 0, 3, 5, 9, 12]
+target = 12
+
+nums = [-1, 0, 3, 5, 9, 12]
+target = -2
+print(binary_search(nums, target))
+
+# def search