Thread: Palindrome Program Help!

Code:

#include <stdio.h>
#include <string.h>
#define MAX 50
#define Null '\0'
int getStringF(char [],int, FILE *);
main()
{
 int b,e,numChar,leng,eof;
 float comp;
 char pal[MAX+1], rpal[MAX+1],temp;
 FILE *payInFile, *payOutFile;
 payInFile = fopen("sample.txt","r");
 payOutFile = fopen("sampout.txt","w");
 fprintf(payOutFile,"Palindrome Program Fall 2011 by Bradley Lantz\n");
 fprintf(payOutFile,"Project #6 Due 12/9/11\n\n");
 fprintf(payOutFile,"Palindrome?    Input String\n");
 numChar = getStringF(pal,MAX,payInFile); //printf here prints 1st string
 leng = numChar;
 for(b=0;b<MAX;b++)
      rpal[b]=0;
 while (numChar!=0)
 {
       temp=0;
       e = leng;
    for (b=0;b!=Null; b++) //b<numChar && e!=0 (condition)
  {
         pal[b] = rpal[leng]; //pal[e-1]
         leng--;
        }
       printf("%s %s", pal, rpal);
    comp = strcmp(pal,rpal);
    if (comp==0)
  fprintf(payOutFile,"YES   %s*\n",pal);
    else
  fprintf(payOutFile,"NO    %s*\n",pal);
    numChar = getStringF(pal,MAX,payInFile); //printf here prints 1st string
    leng = numChar;
 }
 fprintf(payOutFile,"\nEnd of Program, Normal Termination");
 system("pause");
}
int getStringF(char s1[],int max, FILE *in)
{
 char c;
 int p=0;
 c=getc(in);
 while ((c!=EOF) && (c!='\n') && (p < max))
 {
    s1[p]=c;
    p++;
    c=getc(in);
 }
 s1[p] = '\0';
 return p;
}

I can't get my for loop to reverse the array pal into rpal (reverse palindrome). I've tried putting in a temp. I've tried changing the order. Nothing I do works. I just got it to the point now where it'll print out the string properly I just need it to check whether or not the string is a palindrome or not.

That's the thing. The program is supposed to take a line from a file and determine whether or not it's a palindrome. Everything works besides the for loop, and I don't know how to make it work. If I can get that to work then everything else should work, because that's the only problem.

Did you even bother to look at the link I gave you?

You need to STOP writing code, and think about how you determine if a string is a palindrome or not.

You don't need to go all the way to the end of the string!

You need a pointer (or index) at the base of the array (call it left), and you need another one on the end of the string (call it right). While left==right char's, you increment left, and decrement right. When they pass each other in the middle, or left doesn't equal right anymore, the loop should end.

You'll need to handle spaces so you "skip" over them, for both left and right, independently.

Sorry...had a senior moment... :-\

Sorry "had a senior moment" is not a palindrome!

(That's my favorite palindrome chuckle).

This was my last project for my first computer programming class, which I turned in today! I like computer science! I learned how to js inject this morning! I deleted the White House!!!!!!!!!!!!!!!!!

Terminal Velocity of a Cow

Code:

#include<stdio.h>
#include<math.h>
main(){
 float tV,m,g=9.81,cD=0.1,p=1.2754,a,maths;
 printf("How fat is your cow in kilograms?\n");
 scanf("%f",&m);
 printf("How many cubic kilometers does your cow take up?\n");
 scanf("%f",&a);
 maths=((2*m)*g)/((p*a)*cD);
 tV=sqrt(maths);
 printf("At IUPAC standard temperature and pressure and assuming your cow is a\n smooth sphere, the terminal velocity of your cow is: %.2f meters per second.",tV);
 system("pause");
}

Palindrome ++

Code:

#include<stdio.h>
#include<string.h>
int max=50;
int getStringF(char[],int,FILE *);
main()
{
 FILE *oF,*iF;
 oF=fopen("output.txt","w");
 iF=fopen("data6.txt","r");
 fprintf(oF,"Palindrome program Fall 2011 \n");
 fprintf(oF,"Project #6 Due 12/9/11 rundate\n\n");
 fprintf(oF,"Palindrome?  Input string Name: Good Ole Rick. He's a cowboy.\n");
 char string[max];
 int e;
 e=getStringF(string,max,iF);
 while(e!=-1)
 {
  char string2[max]; 
  int i=0,j=0;
  for(i=strlen(string)-1;i>=0;i--)
  { 
   string2[j]=string[i];
   j++;
  }
  string2[j]='\0';
  if((strcmp(string,string2))==0)
   fprintf(oF,"        YES  %s*\n",string);
  else
   fprintf(oF,"         NO  %s*\n",string);
  e=getStringF(string,max,iF);
 }
 fprintf(oF,"\n\n\nEnd of program, Normal Termination");
 fclose(iF);
 fclose(oF);     
}

int getStringF(char string[],int max,FILE *iF)
{
 char c;
 int p=0;
 c=getc(iF);
 while((c!= EOF)&&(c!='\n')&&(p<max))
 {
  string[p]=c;
  p++;
  c=getc(iF);
 }
 string[p]='\0';
 if(c==EOF)
  p=-1;
 return p;  
}

Originally Posted by Adak

Sorry "had a senior moment" is not a palindrome!

(That's my favorite palindrome chuckle).

That's ok my friend... neither is "palindrome"

Re: Post #18,

I'm curious if that second code is what you turned in?

Originally Posted by galvadon

This was my last project for my first computer programming class, which I turned in today! I like computer science! I learned how to js inject this morning! I deleted the White House!!!!!!!!!!!!!!!!!

And now you're giving people their entire homework projects!!!!!!!!!!!!!!

Originally Posted by whiteflags

And now you're giving people their entire homework projects!!!!!!!!!!!!!!

Which doesn't work.

Originally Posted by whiteflags

And now you're giving people their entire homework projects!!!!!!!!!!!!!!

Not to worry... both programs have problems --like in the second one string2 is only valid from line 18 to 24-- so it's unlikely anyone will want to copy them

Sigh... Why do I feel like such a square for indenting and commenting code... Is it cool to not indent or comment? Must have missed the memo.