Package g2001_2100.s2080_range_frequency_queries

Class RangeFreqQuery

java.lang.Object

g2001_2100.s2080_range_frequency_queries.RangeFreqQuery

public class RangeFreqQuery
extends 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 Detail

RangeFreqQuery

public RangeFreqQuery(int[] arr)

Method Detail

query

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