w3resource

Java: Reads a list of pairs of a word and a page number, and prints the word and a list of the corresponding page numbers

Java Basic: Exercise-243 with Solution

Write a Java program that reads a list of pairs of a word and a page number. It prints the words and a list of page numbers.
The number of pairs of a word and a page number is less than or equal to 1000. A word never appear in a page more than once. The words should be printed in alphabetical order and the page numbers should be printed in ascending order.

Input:
Input pairs of a word and a page number:
apple 5
banana 6
Word and page number in alphabetical order:
apple
5
banana
6

Sample Solution:

Java Code:

import java.util.PriorityQueue;
import java.util.Scanner;
 
public class Main {
     
    static class Dic implements Comparable<Dic>{
        String moji;
        int page;
        Dic(String moji, int page){
            this.moji=moji;
            this.page=page;
        }
        public int compareTo(Dic d) {
            if(this.moji.equals(d.moji)) {
                return this.page-d.page;
            }
            else {
                return this.moji.compareTo(d.moji);
            }
        }
    }
     
    public static void main(String[] args) {
        try(Scanner sc = new Scanner(System.in)){
            PriorityQueue<Dic> pq=new PriorityQueue<>();
			System.out.println("Input pairs of a word and a page number:"); 
            while(sc.hasNextLine()) {
                String str=sc.nextLine();
                String[] token=str.split(" ");
                String s=token[0];
                int n=Integer.parseInt(token[1]);
                pq.add(new Dic(s, n));
            }
            String pre="";
           System.out.println("\nWord and page number in alphabetical order:"); 
            while(!pq.isEmpty()) {
                Dic dic=pq.poll();
                if(dic.moji.equals(pre)) {
                    System.out.print(" "+dic.page);
                }
                else if(pre.equals("")) {
                    System.out.println(dic.moji);
                    System.out.print(dic.page);
                }
                else {
                    System.out.println();
                    System.out.println(dic.moji);
                    System.out.print(dic.page);
                }
                pre=dic.moji;
            }
            System.out.println();
        }
    }
}

Sample Output:

Input pairs of a word and a page number:
apple 5
banana 6

Word and page number in alphabetical order:
apple
5
banana
6

Pictorial Presentation:

Java exercises: Reads a list of pairs of a word and a page number, and prints the word and a list of the corresponding page numbers.

Flowchart:

Flowchart: Reads a list of pairs of a word and a page number, and prints the word and a list of the corresponding page numbers.

Flowchart:

Flowchart: Reads a list of pairs of a word and a page number, and prints the word and a list of the corresponding page numbers.

Java Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a Java program which adds up columns and rows of given table as shown in the specified figure.
Next: Write a Java program which accepts a string from the user and check whether the string is correct or not.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.