Difference between sort and stable sort. That is, among elements of the same size, the original element is still in the front after sorting. . Feb 21, 2020 · In the case of HP / Microsoft STL, std::stable_sort is a hybrid bottom up merge sort, using insertion sort to create sorted groups of 32 elements, then doing bottom up merge sort with the groups. It all depends on when two items compare equal in the sort. std::stable_sort would give you the correct answer, while std::sort won't, while the trick I mentioned above would behave like std::stable_sort. std::sort() is a highly efficient, non-stable sorting algorithm. ", but that didn't make sense to me. The so-called stable sorting means that the relative positions of elements of the same size will not change before and after sorting. Jul 23, 2025 · What is a stable sorting algorithm? A sorting algorithm is said to be stable if two objects with equal keys appear in the same order in sorted output as they appear in the input data set Suppose your comparator function merely compares the first elements of strings. The documentation mentions that "Sorts the elements in the range [first,last) into ascending order, like sort, but stable_sort preserves the relative order of the elements with equivalent values. What is the difference between std::sort() and std::stable_sort()? std::sort() and std::stable_sort() are both sorting algorithms provided by the C++ standard library, but they have different characteristics and use cases. A stable sort will leave them in the same relative order while an unstable sort could possibly change the order. pytp oumzo wznu sdogns xjyb hlfrb urmpcr orwd pfxqax jcmxd