> The C++ standard library uses an algorithm called introselect which utilizes a combination of heapselect and quickselect and has an O(nlogn) bound. Introsele

> The C++ standard library uses an algorithm called introselect which utilizes a combination of heapselect and quickselect and has an O(nlogn) bound. Introselect is a combination of Quickselect and Median of Medians and is O(n) worst case.