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--- user:dschoeff:portfolio:palindrome [2011/12/13 02:33] – dschoeff
+++ user:dschoeff:portfolio:palindrome [2011/12/13 03:22] (current) – [Attributes] dschoeff
@@ Line 1: / Line 1: @@
+======Palindrome Program======
+A project for Data Structures by Dave Schoeffler during the Fall 2011 semester.
+This project was begun on December 4th and was finished on December 5th.
+=====Objectives=====
+This project will utilize my Stack Library in creating a program that will check a string to determine whether it is a palindrome or not.
+=====Prerequisites=====
+In order to successfully accomplish/perform this project, the listed resources/experiences need to be consulted/achieved:
+  * Understanding the C programming language
+  * Be familiar with my Stack library
+=====Background=====
+In the course of my computer programming experience, I have done a couple different palindrome programs. One of those used
+array indexing while the other used recursion. This time I will be using stacks to do this task.
+=====Scope=====
+My program will function as follows. I will accept a string from the user. I will then utilize my Stack Library
+to find whether the string is a palindrome or not. I will push() the string I get into two stacks. I will then pop()
+one of the stacks into a 3rd stack. Now stack one and three contain the string forwards and backwards. I will then pop()
+off the top nodes of each of the stacks comparing the values each time. If ever there is a time when the two
+popped nodes are not equal, I know that the string is not a palindrome.
+I will then display the results to the user.
+=====Attributes=====
+The following attributes will be used in my program.
+  * pointers: A pointer will be used to mark the beginning of the array
+  * malloc/new: You must allocate memory for the array
+  * Stacks: this program utilize my stack library
+  * linked lists: my stack library utilizes linked lists
+  * libraries: This program uses a non core libc library
+=====Code=====
+===palindrome.c===
+<code c>
+/***********************************************************
+* Author: Dave Schoeffler                                  *
+* This program will will check to see whether a given      *
+* string is a palindrome. It will utilize my own stack.h   *
+* header file to do this.                                  *
+*                                                          *
+* Compile with: gcc -o palindrome palindrome.c -lstack -L. *
+*                                                          *
+* Execute with: ./palindrome                               *
+*                                                          *
+***********************************************************/
+#include <stdio.h>
+#include <stdlib.h>
+#include "stack.h"
+int count(char *);
+int main()
+{
+   //declaration of 3 stacks that will be used to determine if a string is a palindrome
+   Stack *stack1;
+   Stack *stack2;
+   Stack *stack3;
+   stack1 = stack2 = stack3 = NULL;//initialize them to NULL
+   //The max size string allowed is 50 characters
+   char *ch;
+   ch  =  malloc(sizeof(char)*50);
+   int length, i, flag = 0;
+   printf("Enter a string: ");
+   scanf("%s",ch);
+   length = count(ch);// function count() returns the length of the string given
+   for(i = 0; i < length; i++)//for loop loads the string into stack1
+   {
+      stack1 = push(stack1, *(ch+i));
+   }
+   for(i = 0; i < length; i++)//for loop loads string into stack3
+   {
+      stack3 = push(stack3, *(ch+i));
+   }
+   for(i = 0; i < length; i++)//for loop loads the values from stack one into
+   {                          // stack2 in reverse order
+      stack2 = push(stack2,pop(stack1));
+   }
+   for(i = 0; i < length; i++)//for loop loads the string back into stack1
+   {
+      stack1 = push(stack1,*(ch+i));
+   }
+   //this for loop pops values from stack1 and stack2. if at any point there
+   //is an inequality, flag is set to 1 indicating that the string is not a
+   //palindrome.
+   for( i = 0; i < length; i++)
+   {
+      if(pop(stack1) != pop(stack2))
+      {
+         flag = 1;
+      }
+   }
+   //prints out the string in order and in reverse order
+   printf("Before: %s\n", ch);
+   printf("After: ");
+   for( i = 0; i < length; i++)
+   {
+      printf("%c",pop(stack3));
+   }
+   //prints whether the string is a palindrome or not.
+   printf("\n\"%s\"", ch);
+   if(flag == 1)
+   {
+      printf(" is not a palindrome.\n");
+   }
+   else
+   {
+      printf(" is a palindrome.\n");
+   }
+   return (0);
+}
+// function count() receives as input a string and returns the number
+// of characters in that string as an int
+int count(char *string)
+{
+   int letterCount = 0;
+   while(string[letterCount] != '\0')
+   {
+      letterCount++;
+   }
+   return letterCount;
+}
+</code>
+=====Execution=====
+In the execution of my code, I ran the program twice entering different values each time.
+<cli>
+lab46:~/src/data/eoce/0x1$ ./palindrome
+Enter a string: racecar
+Before: racecar
+After: racecar
+"racecar" is a palindrome.
+lab46:~/src/data/eoce/0x1$ ./palindrome
+Enter a string: datastructures
+Before: datastructures
+After: serutcurtsatad
+"datastructures" is not a palindrome.
+lab46:~/src/data/eoce/0x1$
+</cli>
+=====Reflection=====
+Doing this palindrome project has been a cool experience. I have been able to practice using a stack library that I created which was pretty cool.
+I didn't find to many challenges in this project which I think has to do with being more familiar with linked data structures.
+Overall this was a fun little project to do.
+=====References=====
+In performing this project, the following resources were referenced:
+  * [[http://lab46.corning-cc.edu/user/dschoeff/portfolio/libstack]]

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