find_family_relationship.js

class FamilyTree {
	constructor() {
	  this.relationships = {};
	}
  
	addParent = (parent, child) => {
	  this.relationships[parent] = this.relationships[parent] || new Set();
	  this.relationships[parent].add(child);
	}
  
	isParent = (parent, child) => 
	  this.relationships[parent]?.has(child) || false;
  
	grandparent = (grandparent, grandchild) => 
	  Object.entries(this.relationships).some(([parent, children]) => 
		children.has(grandchild) && this.isParent(grandparent, parent));
  
	sibling = (person1, person2) => 
	  Object.values(this.relationships).some(children => 
		children.has(person1) && children.has(person2) && person1 !== person2);
  
	cousin = (person1, person2) => 
	  Object.entries(this.relationships).some(([parent1, children1]) => 
		children1.has(person1) && 
		Object.entries(this.relationships).some(([parent2, children2]) => 
		  children2.has(person2) && this.sibling(parent1, parent2)));
  
	ancestor = (ancestor, descendant) => {
	  if (this.isParent(ancestor, descendant)) return true;
	  return Array.from(this.relationships[ancestor] || [])
		.some(child => this.ancestor(child, descendant));
	}
  
	familyMembers = (person) => {
	  let members = new Set([person]);
	  Object.entries(this.relationships).forEach(([parent, children]) => {
		if (this.ancestor(parent, person) || parent === person) {
		  members.add(parent);
		  children.forEach(child => members.add(child));
		}
	  });
	  return Array.from(members);
	}
  }
  
  // 사용 예
  const family = new FamilyTree();
  ['john', 'susan'].forEach(parent => ['mary', 'mike'].forEach(child => family.addParent(parent, child)));
  family.addParent('mary', 'ann');
  family.addParent('mary', 'tom');
  family.addParent('mike', 'emma');
  
  console.log(family.grandparent('john', 'ann')); // true
  console.log(family.sibling('mary', 'mike')); // true
  console.log(family.cousin('ann', 'emma')); // true
  console.log(family.ancestor('john', 'emma')); // true
  console.log(family.familyMembers('john')); // ['john', 'mary', 'mike', 'ann', 'tom', 'emma']