Package g2101_2200.s2102_sequentially_ordinal_rank_tracker

Class SORTracker

java.lang.Object
g2101_2200.s2102_sequentially_ordinal_rank_tracker.SORTracker
public class SORTracker extends java.lang.Object
2102 - Sequentially Ordinal Rank Tracker.

Hard

A scenic location is represented by its name and attractiveness score, where name is a unique string among all locations and score is an integer. Locations can be ranked from the best to the worst. The higher the score, the better the location. If the scores of two locations are equal, then the location with the lexicographically smaller name is better.

You are building a system that tracks the ranking of locations with the system initially starting with no locations. It supports:

  • Adding scenic locations, one at a time.
  • Querying the ith best location of all locations already added , where i is the number of times the system has been queried (including the current query).
    • For example, when the system is queried for the 4th time, it returns the 4th best location of all locations already added.

Note that the test data are generated so that at any time , the number of queries does not exceed the number of locations added to the system.

Implement the SORTracker class:

  • SORTracker() Initializes the tracker system.
  • void add(string name, int score) Adds a scenic location with name and score to the system.
  • string get() Queries and returns the ith best location, where i is the number of times this method has been invoked (including this invocation).

Example 1:

Input [“SORTracker”, “add”, “add”, “get”, “add”, “get”, “add”, “get”, “add”, “get”, “add”, “get”, “get”] [ [], [“bradford”, 2], [“branford”, 3], [], [“alps”, 2], [], [“orland”, 2], [], [“orlando”, 3], [], [“alpine”, 2], [], []]

Output: [null, null, null, “branford”, null, “alps”, null, “bradford”, null, “bradford”, null, “bradford”, “orland”]

Explanation:

 SORTracker tracker = new SORTracker(); // Initialize the tracker system.
 tracker.add("bradford", 2); // Add location with name="bradford" and score=2 to the system.
 tracker.add("branford", 3); // Add location with name="branford" and score=3 to the system.
 tracker.get(); // The sorted locations, from best to worst, are: branford, bradford.
             // Note that branford precedes bradford due to its **higher score** (3 > 2).
             // This is the 1<sup>st</sup> time get() is called, so return the best location: "branford". 
 tracker.add("alps", 2); // Add location with name="alps" and score=2 to the system. 
 tracker.get(); // Sorted locations: branford, alps, bradford. 
                 // Note that alps precedes bradford even though they have the same score (2). 
                 // This is because "alps" is **lexicographically smaller** than "bradford". 
                 // Return the 2<sup>nd</sup> best location "alps", as it is the 2<sup>nd</sup> time get() is called. 
 tracker.add("orland", 2); // Add location with name="orland" and score=2 to the system. 
 tracker.get(); // Sorted locations: branford, alps, bradford, orland. 
                 // Return "bradford", as it is the 3<sup>rd</sup> time get() is called. 
 tracker.add("orlando", 3); // Add location with name="orlando" and score=3 to the system. 
 tracker.get(); // Sorted locations: branford, orlando, alps, bradford, orland. 
                 // Return "bradford". 
 tracker.add("alpine", 2); // Add location with name="alpine" and score=2 to the system. 
 tracker.get(); // Sorted locations: branford, orlando, alpine, alps, bradford, orland. 
                 // Return "bradford". 
 tracker.get(); 
                 // Sorted locations: branford, orlando, alpine, alps, bradford, orland. 
                 // Return "orland".

Constraints:

  • name consists of lowercase English letters, and is unique among all locations.
  • 1 <= name.length <= 10
  • 1 <= score <= 105
  • At any time, the number of calls to get does not exceed the number of calls to add.
  • At most 4 * 104 calls in total will be made to add and get.

  • Constructor Summary

    Constructors
    Constructor
    Description
    SORTracker()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(java.lang.String name, int score)
     
    java.lang.String
    get()
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • SORTracker

      public SORTracker()

  • Method Details

    • add

      public void add(java.lang.String name, int score)

    • get

      public java.lang.String get()