O(n+⌊n2⌋+...+⌊nn−1⌋+1)O(n+\lfloor \frac{n}{2} \rfloor+...+\lfloor \frac{n}{n-1} \rfloor+1)O(n+⌊2n⌋+...+⌊n−1n⌋+1)