As the field of computer science becomes more and more advanced

basic algorithms still play important roles in solving complex problems. Selection algorithm is one of the most basic algorithms. It is used to find the kth smallest number in a set or an array. This algorithm is always an important part of more complex problems such as the k nearest neighbors and shortest path problems. The best-known algorithm for this problem is Quickselect which adopts the concept of Divide-and-conquer. The most important problem of this algorithm is to select a good pivot to partition the set. In this paper

I will discuss some existing pivot selecting algorithm and analyze their performance in section 2; then

in the following section

I will discuss a way to improve the algorithm using weighted pivot and show the data that it is indeed a good pivot selection algorithm. Finally

I will discuss further study that is needed to further improve the algorithm.