package algorithm;

import java.io.BufferedOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;

class UnionFind{

    int MAX = 17;
    int father[] = new int[MAX];
    int rank[] = new
 
 int[MAX];
    int indegree[] = new int[MAX];
    int visited[] = new int[MAX];
    HashMap<Integer, ArrayList<Integer>> tree,query;
    int ancestor[] = new int[MAX];
    PrintWriter writer;
    void init(int n){
        for(int i = 1; i <= n; i++){
            father[i] = i;
            rank[i] = 1
 
;
            indegree[i] = 0;
            visited[i] = 0;
            ancestor[i] = 0;

        }
        try {
            writer = new PrintWriter(new BufferedOutputStream(new FileOutputStream("C:\\a.txt")),true);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    int
 
 Find_Set1(int x){
        if(x != father[x])
            father[x] = Find_Set(father[x]);
        return father[x];
    }

    int Find_Set(int x){
        if(x == father[x])
            return x;
        else
            father[x] = Find_Set(father[x]);
        return father[x];
    }

    int Union(int x, int y){
        int a = Find_Set(x);
        int b = Find_Set(y);
        if(a == b)
            return 0;
        if(rank[a] >= rank[b]){
            father[b] = a;
            writer.println("father["+b+"]="+a);
            rank[a] += rank[b];
        }else{
            father[a] = b;
            writer.println("father["+a+"]="+b);
            rank[b] += rank[a];
        }
        return 1;
    }

    void LCA1(int u){
        ancestor[u] = u;
        if(tree.get(u) != null)
            for(int unode : tree.get(u)){
                LCA(unode);
                Union(u, unode);
                ancestor[Find_Set(u)] = u;
            }
        visited[u] = 1;
        if(query.get(u) != null)
            for(int vnode : query.get(u)){
                if(visited[vnode] == 1)
                    System.out.println(u + "和" + vnode +"的最近公共祖先為 ：" + ancestor[Find_Set(vnode)]);
            }
    }

    void LCA(int u){
        //System.out.println("u進入   u= "+u);
        writer.println("u進入   u= "+u);
        ancestor[u] = u;
        //System.out.println("ancestor["+u+"]="+u);
        writer.println("ancestor["+u+"]="+u);
        if(tree.get(u) != null){
            ArrayList<Integer> ulist = tree.get(u);
            for(int unode : ulist){
                LCA(unode);
            //  System.out.println("return ");
            //  System.out.println("合併 "+u +"和"+unode);
                writer.println("return " );
                writer.println("合併 "+u +"和"+unode);
                Union(u, unode);
                ancestor[Find_Set(u)] = u;
            //  System.out.println("Find_Set("+u+")="+Find_Set(u));
            //  System.out.println("ancestor["+u+"]="+Find_Set(u));
                writer.println("Find_Set("+u+")="+Find_Set(u));
                writer.println("ancestor["+Find_Set(u)+"]="+u);
            }
        }
        visited[u] = 1;
    //  System.out.println(u+" 訪問標誌置1");
        writer.println(u+" 訪問標誌置1");
        if(query.get(u) != null){
            writer.println("query "+u+" 不為空");
            ArrayList<Integer> vlist = query.get(u);
            for(int vnode : vlist){
                if(visited[vnode] == 1){
                    System.out.println(u + " 和 " + vnode +" 的最近公共祖先為 ：" + ancestor[Find_Set(vnode)]);
                writer.println(u + " 和 " + vnode +" 的最近公共祖先為 ：" + ancestor[Find_Set(vnode)]);}
            }
        }
    }

    void commonAncestor(int x, int y){
        int n = 16;
        init(n);
        tree = new HashMap<Integer, ArrayList<Integer>>();
        query = new HashMap<Integer, ArrayList<Integer>>();

        ArrayList<Integer> list1 = new ArrayList<Integer>();
        list1.add(5); indegree[5]++;
        list1.add(4);indegree[4]++;
        list1.add(1);indegree[1]++;
        tree.put(8, list1);

        ArrayList<Integer> list2 = new ArrayList<Integer>();
        list2.add(9);indegree[9]++;
        tree.put(5, list2);

        ArrayList<Integer> list3 = new ArrayList<Integer>();
        list3.add(6);indegree[6]++;
        list3.add(10);indegree[10]++;
        tree.put(4, list3);

        ArrayList<Integer> list4 = new ArrayList<Integer>();
        list4.add(14);indegree[14]++;
        list4.add(13);indegree[13]++;
        tree.put(1, list4); 

        ArrayList<Integer> list5 = new ArrayList<Integer>();
        list5.add(15);indegree[15]++;
        list5.add(7);indegree[7]++;
        tree.put(6, list5);

        ArrayList<Integer> list6 = new ArrayList<Integer>();
        list6.add(11);indegree[11]++;
        list6.add(16);indegree[16]++;
        list6.add(2);indegree[2]++;
        tree.put(10, list6);

        ArrayList<Integer> list7 = new ArrayList<Integer>();
        list7.add(3);indegree[3]++;
        list7.add(12);indegree[12]++;
        tree.put(16, list7);


        ArrayList<Integer> q = new ArrayList<Integer>();
        q.add(x);

        ArrayList<Integer> q2 = new ArrayList<Integer>();
        q2.add(y);

        query.put(x, q2);
        query.put(y, q);

        LCA(8);
        /*System.out.println(uf.tree);
        System.out.println(uf.query);
        System.out.println(uf.indegree);
        for(int i = 0; i < indegree.length; i++)
            System.out.print(indegree[i] + " ");

        */
        /*for(int i = 1; i <= n; i++){
            if(indegree[i] == 0){
                uf.LCA(i);
                break;
            }
        }*/
    }
}

//並查集 + DFS 求最近公共祖先
public class UnionFind1 {
    public static void main(String[] a){
        UnionFind uf = new UnionFind();
        uf.commonAncestor(9, 7);
    }
}