def binary_search(arr, target): left, right = 0, len(arr) - 1 while left <= right: mid = (left + right) // 2 if arr[mid] == target: return mid elif arr[mid] < target: left = mid + 1 else: right = mid - 1 return -1
arr = [1, 3, 5, 7, 9] target = 7 print("Element found at index:", binary_search(arr, target))