Question

Using C language

Palindromes

A palindrome is a word or phrase that reads the same backwards and forwards, ignoring punctuation, spaces, and anything that isn’t a letter.

Examples of Palindromes

• Madam, I’m Adam.
• Kayak
• Racecar
• A man, a plan, a canal – Panama!
• Able was I, ere I saw Elba.
• Go hang a salami, I’m a lasagna hog!

Write a program that does the following:

1. opens a text file named “Proj3input.txt” containing multiple lines of text (1 or more)
2. for each line, print out the condensed version of that line of text with all non-alphabetic characters removed, and all alphabetic characters turned into lower case.
3. for each line, print out “Palindrome:” and then the line of text if it IS a palindrome, and print out “Not a palindrome:” and the line of text if it is NOT a palindrome.

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

#include<stdio.h>

#include<string.h>

#include<ctype.h>

//method to remove all non alphabetic characters from a line and store in second parameter

void removeNonAlpha(char *line, char* result){

                int len=strlen(line);

                //looping through the original line

                for(int i=0;i<len;i++){

                                char c=line[i];

                                //checking if c is alphabet

                                if(isalpha(c)){

                                               //converting to lower case, appending to result

                                               c=tolower(c);

                                               strncat(result,&c,1);

                                }

                }

}

//method to check if a line is palindrome (line is formatted prior to the call

//to this method)

int isPalindrome(char* line){

                int len=strlen(line);

                //looping for len/2 times

                for(int i=0;i<len/2;i++){

                                //comparing i'th character from front and rear

                                char c1=line[i];

                                char c2=line[len-1-i];

                                //if they are not same, returning 0 (not palindrome)

                                if(c1!=c2){

                                               return 0;

                                }

                }

                //if tests passed successfully, returning 1

                return 1;

}

int main(){

                //opening Proj3input.txt file

                FILE* file=fopen("Proj3input.txt","r");

                //printing error if file not found

                if(file==NULL){

                                printf("File not found!\nPlease check if Proj3input.txt exists on the same directory\n");

                                return 0;

                }

                char line[150];

                //reading file line by line

                while(fgets(line, 150, file) != NULL){

                                char formatted[150]="";

                                //formatting line (removing non alphabetic chars)

                                removeNonAlpha(line,formatted);

                                //checking if formatted line isPalindrome or not

                                if(isPalindrome(formatted)==1){

                                               printf("Palindrome: %s\n",formatted);

                                }else{

                                               printf("Not a palindrome: %s\n",formatted);

                                }

                }

                //closing file

                fclose(file);

                return 0;

}

/*OUTPUT*/

Palindrome: madamimadam

Not a palindrome: cprogramming

Palindrome: kayak

Not a palindrome: hello

Palindrome: racecar

Palindrome: amanaplanacanalpanama

Palindrome: ablewasiereisawelba

Palindrome: gohangasalamiimalasagnahog

Not a palindrome: haha

//Proj3Input.txt file that I used

Madam, I’m Adam.

C programming

Kayak

Hello

Racecar

A man, a plan, a canal – Panama!

Able was I, ere I saw Elba.

Go hang a salami, I’m a lasagna hog!

Haha