Write a Java program that prompts the user to enter 3 strings, and displays the

Question

Write a Java program that prompts the user to enter 3 strings, and displays the largest common prefix of the three strings. If there is a common prefix display the percentage the common prefix is of the longest string. For example if the largest string is 20 letters and the common prefix is 5 letters then the common prefix is 25% of the longest string. Do not include spaces in that determination. Display a message if there are no common prefixes.

I am having a bit of trouble getting the percent of the longest string to display, any ideas? This is what I have so far:

import java.util.Scanner; public class SecondProgram { public static void main(String[] args) { Scanner sc = new Scanner(System.in); // Prompting user to enter 3 strings System.out.println("Enter the first string: "); String first = sc.nextLine(); System.out.println("Enter the second string: "); String second = sc.nextLine(); System.out.println("Enter the third string: "); String third = sc.nextLine(); // Finding the longest common string int l = first.length(); int p = 0; float percent; if ( first.length() > second.length() && first.length() > third.length() ) l = first.length(); else if ( second.length() > first.length() && second.length() > third.length() ) l = second.length(); else if ( third.length() > first.length() && third.length() > second.length() ) l = third.length(); for (int i = 0; i <= l; i++) { if (first.charAt(i) != first.charAt(i)) { break; } if (first.charAt(i) != third.charAt(i)) { break; } p++; } // Printing common prefix if any if (p == 0) { System.out.println(first + " and " + second + " and " + third + " have no common prefix. "); } // Printing the percentage percent = (p / l) * 100; System.out.println("The common prefix is " + first.substring(0, p)); System.out.println("The common prefix is" + percent + " the longest string. "); if(first.length() > second.length()){ int perc = (first.substring(0, p).length() / second.length() ) *100 ; System.out.println("The common prefix is " + perc + "% of the longest string"); } else{ int perc = (second.substring(0, p).length() / third.length() ) *100 ; System.out.println("The common prefix is " + perc + "% of the longest string"); } } }

Explanation / Answer

SecondProgram.java

import java.text.DecimalFormat;
import java.util.Scanner;

public class SecondProgram {
   public static void main(String[] args) {
       int k = 0;
       //Decimal Format class object is used to format the output
       DecimalFormat df=new DecimalFormat("#.##");
      
       //Scanner class object is used to read the inputs entered by the user
       Scanner sc = new Scanner(System.in);
      
       // Prompting user to enter 3 strings
       System.out.println("Enter the first string: ");
       String first = sc.nextLine();
       System.out.println("Enter the second string: ");
       String second = sc.nextLine();
       System.out.println("Enter the third string: ");
       String third = sc.nextLine();
      
       // Finding the longest common string
       int l = first.length();
       int p = 0;
       float percent;
      
       //Finding longest string length
       if (first.length() > second.length() && first.length() > third.length())
           l = first.length();
       else if (second.length() > first.length() && second.length() > third.length())
           l = second.length();
       else if (third.length() > first.length() && third.length() > second.length())
           l = third.length();
      
       //finding the shortest string length
       if (first.length() < second.length() && first.length() < third.length())
           k = first.length();
       else if (second.length() < first.length() && second.length() < third.length())
           k = second.length();
       else if (third.length() < first.length() && third.length() < second.length())
           k= third.length();
      
       //Finding length of the common prefix
       for (int i = 0; i < k; i++) {
           if (first.charAt(i) != second.charAt(i)) {
               break;
           }
           if (first.charAt(i) != third.charAt(i)) {
               break;
           }
           p++;
       }
       // Printing the error message if there is no common prefix
       if (p == 0) {
           System.out.println("'"+first + "' and '" + second + "' and '" + third+ "' have no common prefix. ");
       }
       else
       {
           // calculating the common prefix percentage
           percent = ((float)p / l) * 100;
          
           //Displaying the common prefix
           System.out.println("The common prefix is '" + first.substring(0, p)+"'");
          
           //Displaying the length of common prefix
           System.out.println("The common prefix is " + p+ " letters . ");
          
           //Displaying the percentage of common prefix of the longest string
           System.out.println("The common prefix is " + df.format(percent)+ "% of the longest string");  
       }
      

   }
}

___________________________

Output1:

Enter the first string:
Hello Singh
Enter the second string:
Hello Roy
Enter the third string:
Hel Sam
The common prefix is 'Hel'
The common prefix is 3 letters .
The common prefix is 27.27% of the longest string

_____________________________

Output2:

Enter the first string:
Hello how are you
Enter the second string:
Am Fine
Enter the third string:
Who are you
'Hello how are you' and 'Am Fine' and 'Who are you' have no common prefix.

_________________________________

Output3:

Enter the first string:
Hello
Enter the second string:
Hel
Enter the third string:
He
The common prefix is 'He'
The common prefix is 2 letters .
The common prefix is 40% of the longest string

_______________________Thank You

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