Java言語プログラム設計とデータ構造」プログラミング練習解答(第21章)(二)
『Java言語プログラム設計とデータ構造』プログラミング練習解答(第21章)(二)
英文名:Introduction to Java Programming and Data Structures,Comprehensive Version,11 th Edition
21.8
21.9
21.10
21.11
21.12
はい、考えました.
21.14
21.14
よじ登る
21.15
忘れた
第二十一章完
英文名:Introduction to Java Programming and Data Structures,Comprehensive Version,11 th Edition
21.8
public class book {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
HashMap<String, Integer> map = new HashMap<>();
System.out.println("enter the xxx");
String xxx = input.nextLine();
String[] words = xxx.split("[\\s,\\,,\\;,\\.,\\:,\\?,\\(,\\),\',\"]");
for (String word : words) {
String key = word.toLowerCase();
if (map.containsKey(key)) {
int occur = map.get(key);
occur++;
map.put(key, occur);
} else {
map.put(key, 1);
}
}
for(Map.Entry<String, Integer> entry: map.entrySet()){
System.out.println(entry.getValue()+"\t"+entry.getKey());
}
}
}
21.9
public class book {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
HashMap<String, String> provinces = new HashMap<>();
provinces.put("Liaoning","Shenyang");
provinces.put("Jilin","Changchun");
provinces.put("Heilongjiang","Ha'erbin");
System.out.println("Please enter a name of a province:");
String pName = input.nextLine();
if(provinces.containsKey(pName)){
System.out.println("The capital of "+pName+" is "+provinces.get(pName));
}
else{
System.out.println("Please enter a valid province name");
}
}
}
21.10
public class book {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
HashMap<String, Integer> keyWords = new HashMap<>();
keyWords.put("int",0);
keyWords.put("double",0);
System.out.println("enter the code");
boolean valid = true;
while(input.hasNext()){
String word = input.next();
if(word.equals("//")){
valid = false;
}else if(word.equals("
")){
valid = true;
}else if(word.equals("\"")){
valid = !valid;
}else{
if(keyWords.containsKey(word)){
int occur = keyWords.get(word);
occur++;
keyWords.put(word, occur);
}
}
}
}
}
21.11
public class book {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
ArrayList<HashMap<String, Integer>> boyRank = new ArrayList<>(10);
//HashMap[] girlRank = new HashMap[10];
for(int i=0;i<10;i++){
boyRank.add(new HashMap<String, Integer>());
}
boyRank.get(0).put("Tom",1);
boyRank.get(0).put("Jerry",2);
boyRank.get(1).put("Jerry",1);
boyRank.get(1).put("Tom",2);
System.out.println("Please enter the year:");
int year = input.nextInt();
System.out.println("Please enter the name:");
String name = input.nextLine();
name = input.nextLine();
System.out.println("The rank is "+boyRank.get(year).get(name));
}
}
21.12
はい、考えました.
21.14
public class book {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
ArrayList<HashMap<String, Integer>> boyRank = new ArrayList<>(10);
//HashMap[] girlRank = new HashMap[10];
for(int i=0;i<10;i++){
boyRank.add(new HashMap<String, Integer>());
}
boyRank.get(0).put("Tom",1);
boyRank.get(0).put("Jerry",2);
boyRank.get(1).put("Jerry",1);
boyRank.get(1).put("Tom",2);
while(true) {
System.out.println("Please enter the year:");
int year = input.nextInt();
System.out.println("Please enter the name:");
String name = input.nextLine();
name = input.nextLine();
System.out.println("The rank is " + boyRank.get(year).get(name));
System.out.println("Enter another query?");
String another = input.nextLine();
if(another.equals("N")){
break;
}
}
}
}
21.14
よじ登る
21.15
忘れた
第二十一章完