Algorithm

Quest:

In English like pseudo-code, or structured English -- just to make sure
everyone can read it; write an algorithm to determine if a string is a
palindrome. A palindrome is a word or phrase that is spelled the same
whether you are reading it forwards or backwards (ex. race car, Madam
I’m Adam). Your algorithm should ignore spaces and punctuation. Make
sure to clearly state your assumptions before presenting your answer and
to justify your use of data structure: what data structure did you
choose (from lists, stacks, queues or trees) and why, and briefly
explain why you did not choose the others

(CAN YOU JUST CHECK IF THE BELOW GIVEN 2 ALGORITHMS ARE CORRECT OR IS
THERE SOME CHANGE THAT CAN BE MADE AND EXPLAIN WHY)

Sol 01

Procedure determinePalindrome ( st as string)

{

   /* ignoring spaces and punctuation */

   Declare a list variable to store the spaces and punctuation
ignored string.  List[ ]

   len= length of st

   Dynamically make the list variable size as length of the string

   Declare i as integer and j as integer

   Initialize k value as 1

   Initialize j value as 1

   Loop

      {

          /* get j th  position character from the st . i.e
if j=1  1st character, j=2 2nd character and so on*/

          

          If character is not a space and character not is not
a punctuation then

              {

                  Add the character to the list

List[k] = character

 Increment k by 1

              }

              Increment j by 1

      } continue until j < = len

     /* determining string is a palindrome or not */

     

    /* here length of the new string is k -1 */

    Declare variable x as integer

    Initialize x with floor(k/2)   /* floor is rounding the
fractions down*/

    Assign j value as 1

    Decrement k value by 1   /* now this the length of the new
string*/

    Loop

    {

      /*Get the j th postion character and k th  character from
the list*/

      If list[x] <> list[k] then

         Display as the given string is not a palindrome

         Exit procedure

      End if

      Increment j by 1

      Decrement k by 1

    } continue until j <=x

   Display as Given String is a palindrome.

}

Sol 2

//In this procedure '=' refers to the assignment statement and '=='
refers to the equal statement

//The array starts with '0' as the first pointer instead of '1'

procedure checkPalindrome (string inputString)

if the length of inputString is less than 2 characters

then

        return error "String too short"

end if

int i, j, k

char stringArray[length of inputString]

i = 0

for (i < length of inputString)

do

        {stringArray[i] = character i of inputString

        i = i + 1

end for

i = 0

j = length of stringArray - 1

k = 0

while (j - i >= 0) and (i <> j) and (k == 0)

do

        if (stringArray[i] is a space or punctutation)

        then {i = i + 1

               }

        else {

               if (stringArray[j] is a space or
punctuation)

               then {j = j - 1

                      }

               else {

                      if (stringArray[i] ==
stringArray[j])

                      then {

                             i = i + 1

                             j = j + 1

                             }

                      else { k == 1}

                      end if

               end if

        endif

end do

if (k == 0)

then {report inputString is a palindrome

        }

else {report inputString is not a palindrome

        }

end if

end procedure