Package g2001_2100.s2080_range_frequency_queries

Class RangeFreqQuery

java.lang.Object
g2001_2100.s2080_range_frequency_queries.RangeFreqQuery
public class RangeFreqQuery extends java.lang.Object
2080 - Range Frequency Queries.

Medium

Design a data structure to find the frequency of a given value in a given subarray.

The frequency of a value in a subarray is the number of occurrences of that value in the subarray.

Implement the RangeFreqQuery class:

  • RangeFreqQuery(int[] arr) Constructs an instance of the class with the given 0-indexed integer array arr.
  • int query(int left, int right, int value) Returns the frequency of value in the subarray arr[left...right].

A subarray is a contiguous sequence of elements within an array. arr[left...right] denotes the subarray that contains the elements of nums between indices left and right ( inclusive ).

Example 1:

Input

 ["RangeFreqQuery", "query", "query"]
 [[[12, 33, 4, 56, 22, 2, 34, 33, 22, 12, 34, 56]], [1, 2, 4], [0, 11, 33]]

Output: [null, 1, 2]

Explanation:

 RangeFreqQuery rangeFreqQuery = new RangeFreqQuery([12, 33, 4, 56, 22, 2, 34, 33, 22, 12, 34, 56]);
 rangeFreqQuery.query(1, 2, 4); // return 1. The value 4 occurs 1 time in the subarray [33, 4]
 rangeFreqQuery.query(0, 11, 33); // return 2. The value 33 occurs 2 times in the whole array.

Constraints:

  • 1 <= arr.length <= 105
  • 1 <= arr[i], value <= 104
  • 0 <= left <= right < arr.length
  • At most 105 calls will be made to query

  • Constructor Summary

    Constructors
    Constructor
    Description
    RangeFreqQuery(int[] arr)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    query(int left, int right, int value)
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • RangeFreqQuery

      public RangeFreqQuery(int[] arr)

  • Method Details

    • query

      public int query(int left, int right, int value)