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.<p>Medium</p> <p>Design a data structure to find the <strong>frequency</strong> of a given value in a given subarray.</p> <p>The <strong>frequency</strong> of a value in a subarray is the number of occurrences of that value in the subarray.</p> <p>Implement the <code>RangeFreqQuery</code> class:</p> <ul> <li><code>RangeFreqQuery(int[] arr)</code> Constructs an instance of the class with the given <strong>0-indexed</strong> integer array <code>arr</code>.</li> <li><code>int query(int left, int right, int value)</code> Returns the <strong>frequency</strong> of <code>value</code> in the subarray <code>arr[left...right]</code>.</li> </ul> <p>A <strong>subarray</strong> is a contiguous sequence of elements within an array. <code>arr[left...right]</code> denotes the subarray that contains the elements of <code>nums</code> between indices <code>left</code> and <code>right</code> ( <strong>inclusive</strong> ).</p> <p><strong>Example 1:</strong></p> <p><strong>Input</strong></p> <pre><code> [&quot;RangeFreqQuery&quot;, &quot;query&quot;, &quot;query&quot;] [[[12, 33, 4, 56, 22, 2, 34, 33, 22, 12, 34, 56]], [1, 2, 4], [0, 11, 33]] </code></pre> <p><strong>Output:</strong> [null, 1, 2]</p> <p><strong>Explanation:</strong></p> <pre><code> 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. </code></pre> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= arr.length <= 10⁵</code></li> <li><code>1 <= arr[i], value <= 10⁴</code></li> <li><code>0 <= left <= right < arr.length</code></li> <li>At most <code>10⁵</code> calls will be made to <code>query</code></li> </ul>

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)