满二叉树

题目：对于一颗满二叉树深度为K，节点是为2^K-1；节点值为1至（2^K-1）。给出K和任意三个节点的值，输出包含改三个节点的最小子树的根节点样例输入：4 10 15 13值样例输出：12

思想：满二叉树——有序的

         二分查找，递归

import java.util.Scanner;

public class Tencent_Main3 {
    public static int GG(int left,int right,int a,int b,int c){
        int mid=(left+right+1)/2;
        if((a<mid)&&(b<mid)&&(c<mid)){
            return GG(left,mid-1,a,b,c);
        }else if((a>mid)&&(b>mid)&&(c>mid)){
            return GG(mid+1,right,a,b,c);
        }else{
            return mid;
        }
    }
    
    public static void SortTree(){
        Scanner sc=new Scanner(System.in);
        while(sc.hasNext()){
            String str=sc.nextLine();
            String[] array=str.split(" ");
            
            int depth=Integer.parseInt(array[0]);
            int a=Integer.parseInt(array[1]);
            int b=Integer.parseInt(array[2]);
            int c=Integer.parseInt(array[3]);
            
            int left=1;
            int right=(int)Math.pow(2, depth)-1;
            int answer=GG(left,right,a,b,c);
            System.out.println(answer);
        }
    }
    
    public static void main(String[] args) {
        SortTree();
    }
}

 

import java.util.Scanner;

public class Tencent_Main4 {
    public static int GG(int left,int right,int a,int b,int c){
        int mid=(left+right)/2;
        if((a<mid)&&(b<mid)&&(c<mid)){
            return GG(left,mid-1,a,b,c);
        }else if((a>mid)&&(b>mid)&&(c>mid)){
            return GG(mid+1,right,a,b,c);
        }else{
            return mid;
        }
    }
    
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        while(sc.hasNext()){
            String str=sc.nextLine();
            String[] array=str.split(" ");
            
            int depth=Integer.parseInt(array[0]);
            int a=Integer.parseInt(array[1]);
            int b=Integer.parseInt(array[2]);
            int c=Integer.parseInt(array[3]);
            
            int left=1;
            int right=(int)Math.pow(2, depth)-1;
            int answer=GG(left,right,a,b,c);
            System.out.println(answer);
        }
    }
}