What is the time complexity Big-O of this algorithm?
The second for-loop while be executed N + N/2 + N/4 +....+ N/N

, the first for-loop decides how much the second for-loop will be executed.

When i = 0, j loops until N

, i = N/2, j loops until N/2

, And so on

, The Big O notation of N + N/2 + N/4 +....+ N/N will be O(N)