Class OrderedStream

java.lang.Object
g1601_1700.s1656_design_an_ordered_stream.OrderedStream

public class OrderedStream extends java.lang.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 Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    java.util.List<java.lang.String>
    insert(int idKey, java.lang.String value)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • OrderedStream

      public OrderedStream(int n)
  • Method Details

    • insert

      public java.util.List<java.lang.String> insert(int idKey, java.lang.String value)