Choose efficient algorithms like quicksort or mergesort, and take advantage of built-in sorting functions.

Sorting is a common task in competitive programming, and optimizing sorting can significantly reduce time complexity. The most commonly used sorting algorithms in competitive programming are quicksort and mergesort, both of which have O(n log n) time complexity. In some cases, you can use built-in sorting functions provided by the programming language, which are usually highly optimized for general cases. Understanding when to use specialized sorting algorithms, such as counting sort or radix sort for specific types of data, can give you an edge. Additionally, sorting small or partially sorted arrays using insertion sort can also improve efficiency in specific cases.