Package g1801_1900.s1825_finding_mk_average

Class MKAverage

java.lang.Object
g1801_1900.s1825_finding_mk_average.MKAverage
public class MKAverage extends java.lang.Object
1825 - Finding MK Average.

Hard

You are given two integers, m and k, and a stream of integers. You are tasked to implement a data structure that calculates the MKAverage for the stream.

The MKAverage can be calculated using these steps:

  1. If the number of the elements in the stream is less than m you should consider the MKAverage to be -1. Otherwise, copy the last m elements of the stream to a separate container.
  2. Remove the smallest k elements and the largest k elements from the container.
  3. Calculate the average value for the rest of the elements rounded down to the nearest integer.

Implement the MKAverage class:

  • MKAverage(int m, int k) Initializes the MKAverage object with an empty stream and the two integers m and k.
  • void addElement(int num) Inserts a new element num into the stream.
  • int calculateMKAverage() Calculates and returns the MKAverage for the current stream rounded down to the nearest integer.

Example 1:

Input [“MKAverage”, “addElement”, “addElement”, “calculateMKAverage”, “addElement”, “calculateMKAverage”, “addElement”, “addElement”, “addElement”, “calculateMKAverage”] [[3, 1], [3], [1], [], [10], [], [5], [5], [5], []]

Output: [null, null, null, -1, null, 3, null, null, null, 5]

Explanation: MKAverage obj = new MKAverage(3, 1); obj.addElement(3); // current elements are [3] obj.addElement(1); // current elements are [3,1] obj.calculateMKAverage(); // return -1, because m = 3 and only 2 elements exist. obj.addElement(10); // current elements are [3,1,10] obj.calculateMKAverage(); // The last 3 elements are [3,1,10]. // After removing smallest and largest 1 element the container will be [3]. // The average of [3] equals 3/1 = 3, return 3 obj.addElement(5); // current elements are [3,1,10,5] obj.addElement(5); // current elements are [3,1,10,5,5] obj.addElement(5); // current elements are [3,1,10,5,5,5] obj.calculateMKAverage(); // The last 3 elements are [5,5,5]. // After removing smallest and largest 1 element the container will be `[5]. // The average of [5] equals 5/1 = 5, return 5`

Constraints:

  • 3 <= m <= 105
  • 1 <= k*2 < m
  • 1 <= num <= 105
  • At most 105 calls will be made to addElement and calculateMKAverage.

  • Constructor Summary

    Constructors
    Constructor
    Description
    MKAverage(int m, int k)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addElement(int num)
     
    int
    calculateMKAverage()
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • MKAverage

      public MKAverage(int m, int k)

  • Method Details

    • addElement

      public void addElement(int num)

    • calculateMKAverage

      public int calculateMKAverage()