Question

Write a program that inputs a string of comma separated test scores from the user and prints out a histogram of the scores. The histogram should have one row on it for each distinct test score, followed by one star for each test score of that value. For example, if the tests scores in the file were 55, 80, 80, 95, 95, 95 and 98, the output to the screen should look like:

55 *

80 **

95 ***

98 *

Answer 1

Please find the code below::

ScoreHistogram.java

package classes1;

import java.util.Map.Entry;
import java.util.Scanner;
import java.util.TreeMap;

public class ScoreHistogram {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       System.out.print("Enter scores comma separated : ");
       String scores = sc.nextLine();
       String scoreRecords[] = scores.split(",");
       TreeMap<String, Integer> scoreMap = new TreeMap<>();
       for(String s : scoreRecords){
           s = s.trim();
           if(scoreMap.containsKey(s)){
               scoreMap.put(s, scoreMap.get(s)+1);
           }else{
               scoreMap.put(s, 1);
           }
       }
       System.out.println("*****************************");
       System.out.println("Score histogram is as below");
       System.out.println("*****************************");
       System.out.printf("%-20s%s\n","Score","Stars");
       for(Entry<String, Integer> entry : scoreMap.entrySet()) //printing map
       {
           System.out.printf("%-20s",entry.getKey());
           for(int i=0;i<entry.getValue();i++){
               System.out.printf("*");
           }
           System.out.println();
       }
   }
}

output: