Package g1601_1700.s1656_design_an_ordered_stream

Class OrderedStream

  • public class OrderedStream
extends Object
    1656 - Design an Ordered Stream.

    Easy

    There is a stream of n (idKey, value) pairs arriving in an arbitrary order, where idKey is an integer between 1 and n and value is a string. No two pairs have the same id.

    Design a stream that returns the values in increasing order of their IDs by returning a chunk (list) of values after each insertion. The concatenation of all the chunks should result in a list of the sorted values.

    Implement the OrderedStream class:

    • OrderedStream(int n) Constructs the stream to take n values.
    • String[] insert(int idKey, String value) Inserts the pair (idKey, value) into the stream, then returns the largest possible chunk of currently inserted values that appear next in the order.

    Example:

    Input [“OrderedStream”, “insert”, “insert”, “insert”, “insert”, “insert”]

    [[5], [3, “ccccc”], [1, “aaaaa”], [2, “bbbbb”], [5, “eeeee”], [4, “ddddd”]]

    Output: [null, [], [“aaaaa”], [“bbbbb”, “ccccc”], [], [“ddddd”, “eeeee”]]

    Explanation:

     // Note that the values ordered by ID is ["aaaaa", "bbbbb", "ccccc", "ddddd", "eeeee"].
 OrderedStream os = new OrderedStream(5);
 os.insert(3, "ccccc"); // Inserts (3, "ccccc"), returns [].
 os.insert(1, "aaaaa"); // Inserts (1, "aaaaa"), returns ["aaaaa"].
 os.insert(2, "bbbbb"); // Inserts (2, "bbbbb"), returns ["bbbbb", "ccccc"].
 os.insert(5, "eeeee"); // Inserts (5, "eeeee"), returns [].
 os.insert(4, "ddddd"); // Inserts (4, "ddddd"), returns ["ddddd", "eeeee"].
 // Concatentating all the chunks returned:
 // [] + ["aaaaa"] + ["bbbbb", "ccccc"] + [] + ["ddddd", "eeeee"] = ["aaaaa", "bbbbb", "ccccc", "ddddd", "eeeee"]
 // The resulting order is the same as the order above.

    Constraints:

    • 1 <= n <= 1000
    • 1 <= id <= n
    • value.length == 5
    • value consists only of lowercase letters.
    • Each call to insert will have a unique id.
    • Exactly n calls will be made to insert.

    • Constructor Detail

      • OrderedStream

        public OrderedStream​(int n)