Binary Search - 1

P1.py

@@ -0,0 +1,29 @@
+# Search in Rotated Sorted Array
+
+class Solution:
+    def search(self, nums: List[int], target: int) -> int:
+        low = 0
+        high = len(nums)-1
+
+        while low<=high:
+            mid = (low+high) // 2
+
+            if nums[mid] == target:
+                return mid
+
+            # Check for left sorted array or not:
+            if nums[low] <= nums[mid]:
+                if nums[low] <= target and nums[mid] >= target:
+                    # target must be here
+                    high = mid-1
+                else:
+                    low = mid+1
+
+            else: 
+                # At this point, it's right sorted
+                if nums[mid] <= target and nums[high]>=target:
+                    low = mid+1
+                else:
+                    high = mid-1
+
+        return -1

P2.py

@@ -0,0 +1,22 @@
+# Search in a sorted array of unknown size
+
+class Solution:
+    def search(self, reader: 'ArrayReader', target: int) -> int:
+        low = 0
+        high = 1
+
+        while reader.get(high) < target:
+            low = high
+            high *= 2
+
+        while low <= high:
+            mid = (low + high) // 2
+
+            if reader.get(mid) == target:
+                return mid
+            elif reader.get(mid) < target:
+                low = mid + 1
+            else:
+                high = mid - 1
+
+        return -1

P3.py

@@ -0,0 +1,23 @@
+class Solution:
+    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:
+        if not matrix or not matrix[0]:
+            return False
+
+        rows = len(matrix)
+        cols = len(matrix[0])
+
+        low = 0
+        high = rows * cols - 1
+
+        while low <= high:
+            mid = (low + high) // 2
+            mid_value = matrix[mid // cols][mid % cols]
+
+            if mid_value == target:
+                return True
+            elif mid_value < target:
+                low = mid + 1
+            else:
+                high = mid - 1
+
+        return False