Check If a String Is Palindrome

Java way to check if a string is palindrome

You can try something like this :

    String variable = ""; #write a string name

    StringBuffer rev = new StringBuffer(variable).reverse(); 

    String strRev = rev.toString(); 

    if(variable.equalsIgnoreCase(strRev)) # Check the condition

Check string for palindrome

Why not just:

public static boolean istPalindrom(char[] word){
    int i1 = 0;
    int i2 = word.length - 1;
    while (i2 > i1) {
        if (word[i1] != word[i2]) {
            return false;
        }
        ++i1;
        --i2;
    }
    return true;
}

Example:

Input is "andna".

i1 will be 0 and i2 will be 4.

First loop iteration we will compare word[0] and word[4]. They're equal, so we increment i1 (it's now 1) and decrement i2 (it's now 3).

So we then compare the n's. They're equal, so we increment i1 (it's now 2) and decrement i2 (it's 2).

Now i1 and i2 are equal (they're both 2), so the condition for the while loop is no longer true so the loop terminates and we return true.

Checking if a string is palindrome

It compares the last character with the first and moves inside the string as follows:

hannah
^    ^

check the two letters are equal: (return False if not)
move the index by 1

hannah
 ^  ^

Do the same check

hannah
  ^^

right index = left index at this point

return True in this case

Check if a string contains palindromes separated by a hash symbol using a vector as an implementation of the stack

A few hints for the first version.

The

while(hashSymbol && !stack.empty()){

Is superfluous. Check just one character at a time.

stack.push_back(s);

pushes the '#' on the stack too.

I think you will have an easier time to adapt your second version rather than correcting the first.

Your not far away from a solution..

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