C++ High Performance

Sorting only for the data you need to retrieve

STL contains three basic sorting algorithms: std::sort(), std::partial_sort(), and std::nth_element(). In addition, it also contains a few abbreviations of those, but we will focus on these three as, in our experience, it is easy to forget that, in many cases, a complete sort can be avoided by using nth_element() or partial_sort() instead.

While std::sort() sorts the whole range, std::partial_sort() and std::nth_element() could be thought of as algorithms for inspecting parts of that sorted range. In many cases, you are only interested in a certain part of the sorted range.

For example;

• If you want to calculate the median of a range, you require the value in the middle of the sorted range.