Package g2201_2300.s2276_count_integers_in_intervals

Class CountIntervals

java.lang.Object
g2201_2300.s2276_count_integers_in_intervals.CountIntervals
public class CountIntervals extends Object
2276 - Count Integers in Intervals.<p>Hard</p> <p>Given an <strong>empty</strong> set of intervals, implement a data structure that can:</p> <ul> <li><strong>Add</strong> an interval to the set of intervals.</li> <li><strong>Count</strong> the number of integers that are present in <strong>at least one</strong> interval.</li> </ul> <p>Implement the <code>CountIntervals</code> class:</p> <ul> <li><code>CountIntervals()</code> Initializes the object with an empty set of intervals.</li> <li><code>void add(int left, int right)</code> Adds the interval <code>[left, right]</code> to the set of intervals.</li> <li><code>int count()</code> Returns the number of integers that are present in <strong>at least one</strong> interval.</li> </ul> <p><strong>Note</strong> that an interval <code>[left, right]</code> denotes all the integers <code>x</code> where <code>left <= x <= right</code>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input</strong></p> <p>[&ldquo;CountIntervals&rdquo;, &ldquo;add&rdquo;, &ldquo;add&rdquo;, &ldquo;count&rdquo;, &ldquo;add&rdquo;, &ldquo;count&rdquo;]</p> <p>[ [], [2, 3], [7, 10], [], [5, 8], []]</p> <p><strong>Output:</strong> [null, null, null, 6, null, 8]</p> <p><strong>Explanation:</strong></p> <pre><code> CountIntervals countIntervals = new CountIntervals(); // initialize the object with an empty set of intervals. countIntervals.add(2, 3); // add [2, 3] to the set of intervals. countIntervals.add(7, 10); // add [7, 10] to the set of intervals. countIntervals.count(); // return 6 // the integers 2 and 3 are present in the interval [2, 3]. // the integers 7, 8, 9, and 10 are present in the interval [7, 10]. countIntervals.add(5, 8); // add [5, 8] to the set of intervals. countIntervals.count(); // return 8 // the integers 2 and 3 are present in the interval [2, 3]. // the integers 5 and 6 are present in the interval [5, 8]. // the integers 7 and 8 are present in the intervals [5, 8] and [7, 10]. // the integers 9 and 10 are present in the interval [7, 10]. </code></pre> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= left <= right <= 10<sup>9</sup></code></li> <li>At most <code>10<sup>5</sup></code> calls <strong>in total</strong> will be made to <code>add</code> and <code>count</code>.</li> <li>At least <strong>one</strong> call will be made to <code>count</code>.</li> </ul>

  • Constructor Details

    • CountIntervals

      public CountIntervals()

  • Method Details

    • add

      public void add(int left, int right)

    • count

      public int count()