With worst case of O(n^2) though? In hindsight it should be possible, since if we use insertion sort, we also get best of O(n) and worst of O(n^2). Though quick select do have average O(n).
Depends if you're talking theory or practice. introselect is worst case O(n) but a lot of implementations implement it with avg case O(n) and worst case O(log n). Median of medians is worst case O(n) but it's slow so mostly avoided.
Depends if you're talking theory or practice. introselect is worst case O(n) but a lot of implementations implement it with avg case O(n) and worst case O(log n). Median of medians is worst case O(n) but it's slow so mostly avoided.