Binary search 1

inf_array_search

@@ -0,0 +1,20 @@
+def search(reader: ArrayReader, target):
+    left, right = 0, 1
+    while reader.get(right) < (2**31 - 1):
+        if reader.get(right) >= target:
+            break
+        left = right
+        right *= 2
+
+    while left <= right:
+        mid = left + (right - left) // 2
+        val = reader.get(mid)
+
+        if val == target:
+            return mid
+        elif val > target or val == (2**31 - 1):
+            right = mid - 1
+        else:
+            left = mid + 1
+
+    return -1 

matrix_search.py

@@ -0,0 +1,21 @@
+class Solution:
+    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:
+        if not matrix or not matrix[0]:
+            return False 
+
+        m, n = len(matrix), len(matrix[0])
+        left, right = 0, m * n - 1
+
+        while left <= right:
+            mid = (left + right) // 2
+            row = mid // n 
+            col = mid % n
+
+            if matrix[row][col] == target:
+                return True
+            elif matrix[row][col] < target:
+                left = mid + 1
+            else:
+                right = mid - 1
+
+        return False

rotated_search.py

@@ -0,0 +1,27 @@
+class Solution:
+    def search(self, nums: List[int], target: int) -> int:
+
+        left = 0
+        right = len(nums)-1
+        while left<=right:
+            mid = (left+right)//2
+
+            if target == nums[mid]:
+                return mid
+
+            elif (left == mid == right) : 
+                return -1
+
+            elif nums[mid]>=nums[left]:
+                if nums[left]<=target<nums[mid]:
+                    right = mid
+                else:
+                    left = mid+1
+
+            else:
+                if nums[mid]<target<nums[left]:
+                    left = mid+1
+                else:
+                    right = mid
+        return -1
+