Package g2201_2300.s2276_count_integers_in_intervals

Class CountIntervals

  • public class CountIntervals
extends Object
    2276 - Count Integers in Intervals.

    Hard

    Given an empty set of intervals, implement a data structure that can:

    • Add an interval to the set of intervals.
    • Count the number of integers that are present in at least one interval.

    Implement the CountIntervals class:

    • CountIntervals() Initializes the object with an empty set of intervals.
    • void add(int left, int right) Adds the interval [left, right] to the set of intervals.
    • int count() Returns the number of integers that are present in at least one interval.

    Note that an interval [left, right] denotes all the integers x where left <= x <= right.

    Example 1:

    Input

    [“CountIntervals”, “add”, “add”, “count”, “add”, “count”]

    [ [], [2, 3], [7, 10], [], [5, 8], []]

    Output: [null, null, null, 6, null, 8]

    Explanation:

     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].

    Constraints:

    • 1 <= left <= right <= 109
    • At most 105 calls in total will be made to add and count.
    • At least one call will be made to count.

    • Constructor Detail

      • CountIntervals

        public CountIntervals()

    • Method Detail

      • add

        public void add​(int left,
                int right)

      • count

        public int count()