给定数组 [1,5,11,30,45,47,47,50]，若要查找某一元素是否存在，使用二分查找，则至多需要查找（）次。

def binary_search(arr, target): left, right = 0, len(arr) – 1 count = 0 while left <= right: mid = (left + right) // 2 count += 1 if arr[mid] == target: print("查找次数：", count) return True elif arr[mid] < target: left = mid + 1 else: right = mid – 1 print("查找次数：", count) return False arr = [1,5,11,30,45,47,47,50] target = 47 if binary_search(arr, target): print("元素存在") else: print("元素不存在")

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