第二次作业

 1 import java.util.HashMap;
 2 import java.util.Iterator;
 3 import java.util.Scanner;
 4 
 5 public class demo {
 6 
 7     public static void main(String[] args) {
 8         
 9         Scanner scanner = new Scanner(System.in);
10         System.out.println("请输入一段英文：");
11         String s = scanner.nextLine();
12         SPLIT(s);
13     }
14     
15     public static void SPLIT(String s){
16         String[] arr=  s.split(" ");
17         HashMap<String, Integer> map = new HashMap<String, Integer>();
18         for(int i=0;i<arr.length;i++){
19              if (!map.containsKey(arr[i])) {
20                  map.put(arr[i], 1);
21              } else {
22                  map.put(arr[i],map.get(arr[i])+1 );
23              }
24         }
25         
26         Iterator iterator = map.keySet().iterator();
27         while(iterator.hasNext()){
28             String string = (String) iterator.next();
29             System.out.println("单词："+string+",共出现了"+map.get(string)+"次。");
30         }
31     }
32 }

1 @Test
2     public void TestSPLIT(){
3         String s = "abc cn cn cn abc cn";
4         demo.SPLIT(s);
5     }

 1 import java.util.Scanner;
 2 
 3 
 4 public class demo2 {
 5 
 6     public static void main(String[] args) {
 7 
 8         Scanner scanner = new Scanner(System.in);
 9         System.out.println("请输入一段英文：");
10         String s = scanner.nextLine();
11         System.out.println(reverse(s));
12     }
13 
14     private static String reverse(String s) {
15         String[] arr=  s.split(" ");
16         String string="";
17         int i = arr.length-1;
18         for( ;i>=0;i--){
19             if(i==0){
20                 string += arr[i];
21                 break;
22             }
23             string += arr[i]+" ";
24         }
25         return string;
26     }
27 
28 }

1 @Test
2     public void testreverse() {
3         String s1 = "how are you";
4         String s2 = demo2.reverse(s1);
5         Assert.assertEquals(s2, "you are how"); 
6     }