g1501_1600.s1600_throne_inheritance.ThroneInheritance

public class ThroneInheritance extends Object

1600 - Throne Inheritance.Medium A kingdom consists of a king, his children, his grandchildren, and so on. Every once in a while, someone in the family dies or a child is born. The kingdom has a well-defined order of inheritance that consists of the king as the first member. Let’s define the recursive function <code>Successor(x, curOrder)</code>, which given a person <code>x</code> and the inheritance order so far, returns who should be the next person after <code>x</code> in the order of inheritance. Successor(x, curOrder): if x has no children or all of x’s children are in curOrder: if x is the king return null else return Successor(x’s parent, curOrder) else return x’s oldest child who’s not in curOrder For example, assume we have a kingdom that consists of the king, his children Alice and Bob (Alice is older than Bob), and finally Alice’s son Jack. <ol> <li>In the beginning, <code>curOrder</code> will be <code>["king"]</code>.</li> <li>Calling <code>Successor(king, curOrder)</code> will return Alice, so we append to <code>curOrder</code> to get <code>["king", "Alice"]</code>.</li> <li>Calling <code>Successor(Alice, curOrder)</code> will return Jack, so we append to <code>curOrder</code> to get <code>["king", "Alice", "Jack"]</code>.</li> <li>Calling <code>Successor(Jack, curOrder)</code> will return Bob, so we append to <code>curOrder</code> to get <code>["king", "Alice", "Jack", "Bob"]</code>.</li> <li>Calling <code>Successor(Bob, curOrder)</code> will return <code>null</code>. Thus the order of inheritance will be <code>["king", "Alice", "Jack", "Bob"]</code>.</li> </ol> Using the above function, we can always obtain a unique order of inheritance. Implement the <code>ThroneInheritance</code> class: <ul> <li><code>ThroneInheritance(string kingName)</code> Initializes an object of the <code>ThroneInheritance</code> class. The name of the king is given as part of the constructor.</li> <li><code>void birth(string parentName, string childName)</code> Indicates that <code>parentName</code> gave birth to <code>childName</code>.</li> <li><code>void death(string name)</code> Indicates the death of <code>name</code>. The death of the person doesn’t affect the <code>Successor</code> function nor the current inheritance order. You can treat it as just marking the person as dead.</li> <li><code>string[] getInheritanceOrder()</code> Returns a list representing the current order of inheritance excluding dead people.</li> </ul> Example 1: Input [“ThroneInheritance”, “birth”, “birth”, “birth”, “birth”, “birth”, “birth”, “getInheritanceOrder”, “death”, “getInheritanceOrder”] [[“king”], [“king”, “andy”], [“king”, “bob”], [“king”, “catherine”], [“andy”, “matthew”], [“bob”, “alex”], [“bob”, “asha”], [null], [“bob”], [null]] Output: [null, null, null, null, null, null, null, [“king”, “andy”, “matthew”, “bob”, “alex”, “asha”, “catherine”], null, [“king”, “andy”, “matthew”, “alex”, “asha”, “catherine”]] Explanation: ThroneInheritance t= new ThroneInheritance(“king”); // order: king t.birth(“king”, “andy”); // order: king > andy t.birth(“king”, “bob”); // order: king > andy > bob t.birth(“king”, “catherine”); // order: king > andy > bob > catherine t.birth(“andy”, “matthew”); // order: king > andy > matthew > bob > catherine t.birth(“bob”, “alex”); // order: king > andy > matthew > bob > alex > catherine t.birth(“bob”, “asha”); // order: king > andy > matthew > bob > alex > asha > catherine t.getInheritanceOrder(); // return [“king”, “andy”, “matthew”, “bob”, “alex”, “asha”, “catherine”] t.death(“bob”); // order: king > andy > matthew > bob > alex > asha > catherine t.getInheritanceOrder(); // return [“king”, “andy”, “matthew”, “alex”, “asha”, “catherine”] Constraints: <ul> <li><code>1 <= kingName.length, parentName.length, childName.length, name.length <= 15</code></li> <li><code>kingName</code>, <code>parentName</code>, <code>childName</code>, and <code>name</code> consist of lowercase English letters only.</li> <li>All arguments <code>childName</code> and <code>kingName</code> are distinct.</li> <li>All <code>name</code> arguments of <code>death</code> will be passed to either the constructor or as <code>childName</code> to <code>birth</code> first.</li> <li>For each call to <code>birth(parentName, childName)</code>, it is guaranteed that <code>parentName</code> is alive.</li> <li>At most <code>105</code> calls will be made to <code>birth</code> and <code>death</code>.</li> <li>At most <code>10</code> calls will be made to <code>getInheritanceOrder</code>.</li> </ul>

Constructor Summary

Constructors

Constructor

Description

ThroneInheritance(String kingName)
Method Summary

Modifier and Type

Method

Description

void

birth(String parentName, String childName)

void

death(String name)

void

dfs(Map<String,LinkedHashSet<String>> graph, String src, List<String> l, Set<String> visited)

List<String>

getInheritanceOrder()

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- ThroneInheritance
  
  public ThroneInheritance(String kingName)
Method Details
- birth
 
 public void birth(String parentName, String childName)
- death
 
 public void death(String name)
- getInheritanceOrder
 
 public List<String> getInheritanceOrder()
- dfs
 
 public void dfs(Map<String,LinkedHashSet<String>> graph, String src, List<String> l, Set<String> visited)

Class ThroneInheritance

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Details

ThroneInheritance

Method Details

birth

death

getInheritanceOrder

dfs