Kaosar and AND#12324

Kaosar and AND (Editorial)

Problem Author:	AlKaosar Hussain
Prepared by:	AlKaosar Hussain
Edited by:	Hasan Saleh (MathModel)

Solution

Notice that for two integers $x, y$ that $x AND y \leq min (x, y)$ x \ \mathtt{AND} \ y \le \min(x,y) , because at the best case which is $x = y$ where both $x$ and $y$ share all turned on bits , which can be at most equal to $min (x, y)$ \min(x,y) , thus the best option is just to choose the maximum element of the array (subsequence of length $1$ ).

1 \leq i \leq n max a_{i}

\boxed{\underset{1 \le i \le n}{\max a_i}}

Complexity $O (n)$ .

for _ in range(int(input())):
    n=int(input())
    a=list(map(int,input().split()))
    print(max(a))