s30 completed Binary-Search-1

2dmatrix.py

@@ -0,0 +1,25 @@
+from typing import List
+
+class Solution:
+    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:
+        rows, cols = len(matrix), len(matrix[0])
+
+        left, right = 0, rows * cols - 1
+
+        while left <= right:
+            mid = (left + right) // 2
+
+            # Convert 1D index to 2D coordinates
+            r = mid // cols
+            c = mid % cols
+
+            val = matrix[r][c]
+
+            if val == target:
+                return True
+            elif val < target:
+                left = mid + 1
+            else:
+                right = mid - 1
+
+        return False

rotated_sorted_array_search.py

@@ -0,0 +1,26 @@
+from typing import List
+class Solution:
+    def search(self, nums: List[int], target: int) -> int:
+        left, right = 0, len(nums) - 1
+
+        while left <= right:
+            mid = (left + right) // 2
+
+            if nums[mid] == target:
+                return mid
+
+            # Left half is sorted
+            if nums[left] <= nums[mid]:
+                if nums[left] <= target < nums[mid]:
+                    right = mid - 1
+                else:
+                    left = mid + 1
+
+            # Right half is sorted
+            else:
+                if nums[mid] < target <= nums[right]:
+                    left = mid + 1
+                else:
+                    right = mid - 1
+
+        return -1

search_sorted_array_uknown_size.py

@@ -0,0 +1,29 @@
+# """
+# This is ArrayReader's API interface.
+# You should not implement it, or speculate about its implementation
+# """
+# class ArrayReader:
+#    def get(self, index: int) -> int:
+
+class Solution:
+    def search(self, reader: 'ArrayReader', target: int) -> int:
+        left, right = 0, 1
+
+        # Find a range containing target
+        while reader.get(right) < target:
+            left = right
+            right *= 2
+
+        # Binary Search
+        while left <= right:
+            mid = (left + right) // 2
+            num = reader.get(mid)
+
+            if num == target:
+                return mid
+            elif num < target:
+                left = mid + 1
+            else:
+                right = mid - 1
+
+        return -1