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Display & Count Palindromic Words

ISC 2013 Computer Science Practical, Question 3 · Strings

The question

A palindrome is a word that may be read the same way in either direction. Accept a sentence in UPPER CASE which is terminated by either “.”, “?”, or “!”. Each word of the sentence is separated by a single blank space.

Perform the following tasks: a) display the count of palindromic words in the sentence. b) Display the palindromic words in the sentence.

Example of palindromic words:

MADAM, ARORA, NOON

Test your program with the sample data and some random data:

Example 1
INPUT:  MOM AND DAD ARE COMING AT NOON.
OUTPUT: MOM DAD NOON
        NUMBER OF PALINDROMIC WORDS: 3

Example 2
INPUT:  NITIN ARORA USES LIRIL SOAP.
OUTPUT: NITIN ARORA LIRIL
        NUMBER OF PALINDROMIC WORDS: 3

Example 3
INPUT:   HOW ARE YOU?
OUTPUT:  NO PALINDROMIC WORDS

Question: ISC 2013 Computer Science Paper 2 (Practical), Question 3, set by the Council for the Indian School Certificate Examinations (CISCE). Solution and video: Vinay Singh.

Java solution

ISC2013Q3.java Download GitHub

import java.util.*;

class Palindrome {
    private String sentence, answer;
    private int frequency;

    public Palindrome(String sentence) {
        this.sentence = sentence;
        frequency = 0;
        answer = "";
        process();
    }

    private boolean isPalindrome(String word) {
        int half = word.length() / 2;
        for (int position = 0; position < half; position++) {
            if (word.charAt(position) != word.charAt(word.length() - 1 - position))
                return false;
        }
        return true;
    }

    private void process(){
        char ch;
        String delimters=".?! ",word="";
        for( int position=0; position<sentence.length();position++){
            ch = sentence.charAt(position);
            if(delimters.indexOf(ch)>=0){
                if(isPalindrome(word)){
                    answer+=word+" ";
                    frequency++;
                }
                word="";
            }else{
                word+=ch;
            }
        }
    }
    public int getFrequency(){
        return frequency;
    }
    public String toString(){
        return answer.trim();
    }
}

public class ISC2013Q3 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("INPUT:\t");
        String sentence = in.nextLine();
        Palindrome objPalindrome = new Palindrome(sentence);
        System.out.print("OUTPUT:\t");
        if(objPalindrome.getFrequency()>0){
            System.out.println(objPalindrome);
            System.out.println("\tNUMBER OF PALINDROMIC WORDS: "+objPalindrome.getFrequency());
        }else{
            System.out.println("NO PALINDROMIC WORDS");
        }
        in.close();
    }
}

Display & Count Palindromic Words

The question

Java solution

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