Homework SourseHello I need help with my program I cant seem to get the exp
Hello, I need help with my program. I can\'t seem to get the expected output. Here are my results for the program.
Program Output
Expected Output
Here is my program, which consists of two files.
1st file (This one does not need to be modified):
import java.io.*;
public class Assignment11
{
public static void main (String[] args) throws IOException
{
char input1;
String line = new String();
printMenu();
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader stdin = new BufferedReader(isr);
do // will ask for user input
{
System.out.println(\"What action would you like to perform?\");
line = stdin.readLine();
input1 = line.charAt(0);
input1 = Character.toUpperCase(input1);
if (line.length() == 1)
{
// matches one of the case statements
switch (input1)
{
case \'E\': //Enter Problem parameters
System.out.print(\"Please enter a string to check:\ \");
String inputString = stdin.readLine().trim();
//create an object of PalindromeChecker using the input string
PalindromeChecker checker = new PalindromeChecker(inputString);
checker.check();
break;
case \'Q\': //Quit
break;
case \'?\': //Display Menu
printMenu();
break;
default:
System.out.print(\"Unknown action\ \");
break;
}
}
else
{
System.out.print(\"Unknown action\ \");
}
} while (input1 != \'Q\' || line.length() != 1);
}
/** The method printMenu displays the menu to a user**/
public static void printMenu()
{
System.out.print(\"Choice\\t\\tAction\ \" +
\"------\\t\\t------\ \" +
\"E\\t\\tEnter String\ \" +
\"Q\\t\\tQuit\ \" +
\"?\\t\\tDisplay Help\ \ \");
}
}
2nd File (I marked what section I need help with ):
import java.util.Stack;
import java.util.LinkedList;
public class PalindromeChecker
{
private Stack charStack; //stack can contain characters
private LinkedList charQueue; //queue can contain characters
private String inputString;
//Constructor to initialize member variables
public PalindromeChecker(String inputString)
{
charStack = new Stack();
charQueue = new LinkedList();
this.inputString = inputString;
}
//The check method checks if an input string is a palindrome or not,
//and prints its result.
public void check()
{
boolean success = true; //success indicates whether palindrome or not
boolean done = false; //it is used to stop the while loop
int i = 0; //i wil be used as an index of the inputString
/***This section below is the code I need help with***/
while (!done)
{
//until the end of inputString or it encounters \'#\' character
//take each character in inputString from left and add it to charStack and charQueue
while(true){
if(i == inputString.length())
break;
else if(inputString.charAt(i) == \'#\'){
break;
}
char ch = inputString.charAt(i);
charStack.push(ch);
charQueue.add(ch);
++i;
}
//prints out the substring extracted from the input string using queue\'s toString method
System.out.print(\"The input \" + charQueue.toString());
//until the charQueue or charStack becomes empty
//remove a character from each of charStack and charQueue, and check if they are same.
//If they are different, then print out the approproate message (\" is not a palindrome\ \")
//and also print which first set of two characters are different
//(\"The characters \' \' and \' \' do not match\ \ \") -- note that you need to print
//two such characters inbetween \' \'
//Also set success to false, so that the following \"if\" statement will be skipped
char ch1, ch2;
success = true;
while(!charQueue.isEmpty()){
ch1 = charQueue.pop();
ch2 = charStack.pop();
if(ch1 != ch2){
System.out.print(\" is not a palindrome \ The characters \'\"
+ ch1 + \"\' and \'\" + ch2 + \"\' do not match\ \ \");
success = false;
break;
}
}
/***End section of code I need help with***/
if (success == true)
System.out.print(\" is a palindrome\ \ \");
//i reaches the end of string, it is done processing the inputString
if (i == inputString.length())
done = true;
else
{
i++;
success = true; //set it back to true for the next substring to check
}
} //end of while loop
} //end of check( ) method
} // end of PalindromeChecker class
Solution
Hi,
The problem which is there in the code is if your string contains more than one palindrome string separated by \'#\', for example consider the string \"deified#racecar\". This has two palindrom strings in it deified and racecar.
For these type of cases the code above will not give the desired output.
Solution: The solution for this will be to clear the stack and queue before testing the second (and third) words.Otherwise letters from first word will invalidate your result.
I have modified the code snippet below which will guide you how to do it:
/*** This section below is the code i need help with ***/
while (!done) {
charStack.clear(); // Clear the stack. charQueue.clear(); //Clear the queue //until the end of input string or it encounters a \'#\' charactertake each char in input String from left and add it to //charStack and charQueue. while (true) {
if(i == inputString.length())
break;
else if(inputString.charAt(i) == \'#\'){
break;
}
char ch = inputString.charAt(i);
charStack.push(ch);
charQueue.add(ch);
++i;
}
//prints out the substring extracted from the input string using queue\'s toString method
System.out.print(\"The input \" + charQueue.toString());
//until the charQueue or charStack becomes empty
//remove a character from each of charStack and charQueue, and check if they are same.
//If they are different, then print out the approproate message (\" is not a palindrome\ \")
//and also print which first set of two characters are different
//(\"The characters \' \' and \' \' do not match\ \ \") -- note that you need to print
//two such characters inbetween \' \'
//Also set success to false, so that the following \"if\" statement will be skipped
char ch1, ch2;
success = true;
while(!charQueue.isEmpty()){
ch1 = charQueue.pop();
ch2 = charStack.pop();
if(ch1 != ch2){
System.out.print(\" is not a palindrome \ The characters \'\"
+ ch1 + \"\' and \'\" + ch2 + \"\' do not match\ \ \");
success = false;
break;
}
}
/***End section of code I need help with***/
Note: The changes done in this code as part of my answer is clearing the charStack and charQueue
Please let me know in case you face any difficulties in this answer.
Thanks & Regards,
Tushar
