# sort stl

The sort function in the C++ Standard Library (STL) is used to arrange elements in a specified range in a particular order. It takes two iterators, representing the range of elements, as parameters.

The sort function follows the Quicksort algorithm, which is a divide-and-conquer sorting algorithm. The steps involved in the sort function are as follows:

The sort function selects a pivot element from the range. This pivot element is used to divide the range into two parts: elements smaller than the pivot and elements greater than the pivot.

The sort function then recursively applies the same steps to each of the two parts created in the previous step. This is done until the range is completely sorted.

During the partitioning process, the sort function rearranges the elements so that all elements smaller than the pivot are placed before it, and all elements greater than the pivot are placed after it. This is done by swapping elements as necessary.

After the partitioning process is completed, the sort function repeats steps 1-3 for the two parts created during the partitioning process. This recursive process continues until the range is completely sorted.

Once the sort function has finished sorting the range, the elements will be arranged in ascending order by default. If a different order is desired, a comparison function can be provided as an optional parameter to the sort function.

It's important to note that the sort function has an average time complexity of O(n log n), where n is the number of elements in the range. However, in the worst case scenario, the time complexity can be O(n^2), which occurs when the pivot element selected is either the smallest or largest element in the range.

Overall, the sort function in the C++ STL provides a convenient and efficient way to sort elements in a range using the Quicksort algorithm.