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"],[],["bob"],[]]
Output: [null,null,null,null,null,null,null,["king","andy","matthew","bob","alex","asha","catherine"],null,["king","andy","matthew","alex","asha","catherine"]]
A kingdom consists of a king and his children in a family tree. Every person has a unique name.
The king has the name kingName. You should support the following operations:
ThroneInheritance(string kingName) Initializes the data structure with the king.void birth(string parentName, string childName) Indicates parentName gave birth to childName.void death(string name) Indicates that name has died.string[] getInheritanceOrder() Returns the current inheritance order.Inheritance follows preorder traversal from the king (parent before children, older children before younger). Dead people are skipped in the final order.
1 <= kingName.length, parentName.length, childName.length, name.length <= 15kingName, parentName, childName, and name consist of lowercase English letters.childName values are unique.parentName always exists when calling birth.death(name) is called only for people that are alive.10^5 calls will be made to birth, death, and getInheritanceOrder in total.