[Java面試考題]Map處理－D奈老師的部落格

今天去松凌科技面試時遇到的考題
限時30分鐘
做出來後我問了一下面試官說能不能把考題公佈
面試官很慷慨的答應了，表示說他們也希望大家都能夠會處理map
於是我回家後馬上將這題題目重現
中文的註解可能有些誤差，以下是題目跟參考解答
題目詳細內容請見註解




import java.util.HashMap;

import java.util.Map;



public class RightLeft {

 

 Map<String, Integer> left;

 Map<String, Integer> right;

 

 public void setUp(){

  left = new HashMap<String, Integer>();

  left.put("a", 1);

  left.put("b", 2);

  left.put("c", 3);

  

  right = new HashMap<String, Integer>();

  right.put("b", 2);

  right.put("c", 4);

  right.put("d", 5);

  

 }

 

 /*

  * <pre>

  * 備住：有兩個Map left right，請在Test()內完成程式碼輸出以下內容

  *

  * 1.key一樣value不一樣的內容

  * 2.key一樣value一樣的內容

  * 3.key只存在left不存在right的內容

  * 4.key只存在right不存在left的內容

  *

  */

 

 public void Test(){

  

  //answer of 1

  System.out.println("1.");

  for(Object key:left.keySet()){

   if(right.get(key)!=null){

    if(!right.get(key).equals(left.get(key))){

     System.out.println("left key="+key+", value="+left.get(key));

     System.out.println("right key="+key+", value="+right.get(key));

    }

   }   

  }

  

  //answer of 2

  System.out.println("2.");

  for(Object key:left.keySet()){

   if(right.get(key)!=null){

    if(right.get(key).equals(left.get(key))){

     System.out.println("left: key="+key+", value="+left.get(key));

     System.out.println("right: key="+key+", value="+right.get(key));

    }

   }   

  }

  

  //answer of 3

  System.out.println("3.");

  for(Object key:left.keySet()){

   if(right.get(key)==null){  

     System.out.println("left: key="+key+", value="+left.get(key));    

   }   

  }

  

  //answer of 4

  System.out.println("4.");

  for(Object key:right.keySet()){

   if(left.get(key)==null){

    

     System.out.println("right: key="+key+", value="+right.get(key));

    

   }   

  }

  

  

 }

 

  

 

 public static void main(String[] args) {

  RightLeft demo = new RightLeft();

  demo.setUp();

  demo.Test();



 }



}