Thread: Bubble Sort from Input File

Welcome to the forum, creilly!

Why do you want a bubble sort code, and where is it, if you do? You just want to use the tree for the sorting, maybe?

Originally Posted by Adak

Welcome to the forum, creilly!

Why do you want a bubble sort code, and where is it, if you do? You just want to use the tree for the sorting, maybe?

Woops, i didnt mean to say bubble sort haha. But ya, the code I posted works for sorting alphabetically, I just need to implement the read/scan from an input file and print the position number next to the letter as seen in the example link.

Alright, I got the code to work, but it only works for inputs that are a single character. How can I get it to work if the input were a word instead of just a letter? I tried using strings but I get segmentations errors.

Code:

#include <stdio.h>
#include <stdlib.h>

struct tnode {
 char data;
 struct tnode *left;
 struct tnode *right;
};

struct tnode *tnode_insert(struct tnode *p, char value);
void print_inorder(struct tnode *p);


int main(void) {
 char demo_nr[50], tmp;
 struct tnode *root = NULL;
 int i=0, k=1, count=0, j;
 FILE *fp;

 fp=fopen("p2_input.txt", "r");

 while(k!=0){
        fscanf(fp, "%d %c", &k, &tmp);
        demo_nr[count]=tmp;
        count++;
 }

 for(i=0; i<count; i++)
  root = tnode_insert(root, demo_nr[i]);
 for(j=0; j<count; j++){
        printf("%d ", j);
 }
         printf("\n");
         print_inorder(root);
         printf("\n");
 return 0;
}

struct tnode *tnode_insert(struct tnode *p, char value) {
 struct tnode *tmp_one = NULL;
 struct tnode *tmp_two = NULL;

 if(p == NULL) {
  p = (struct tnode *)malloc(sizeof(struct tnode));
  p->data = value;
  p->left = p->right = NULL;
 } else {
  tmp_one = p;

  while(tmp_one != NULL) {
   tmp_two = tmp_one;
   if(tmp_one ->data > value)
    tmp_one = tmp_one->left;
   else
    tmp_one = tmp_one->right;
  }

  if(tmp_two->data > value) {
   tmp_two->left = (struct tnode *)malloc(sizeof(struct tnode));
   tmp_two = tmp_two->left;
   tmp_two->data = value;
   tmp_two->left = tmp_two->right = NULL;
  } else {
   /* insert [new] tnode as left child */
   tmp_two->right = (struct tnode *)malloc(sizeof(struct tnode));
   tmp_two = tmp_two->right;
   tmp_two->data = value;
   tmp_two->left = tmp_two->right = NULL;
  }
 }

 return(p);
}

void print_inorder(struct tnode *p){
 int j=0;
 if(p!=NULL) {
    print_inorder(p->left);
    printf("%c ", p->data);
    print_inorder(p->right);
 }
}

You have your data variable as type char. Of course it won't work as a string of char's - since it only will hold just one char.

In C, one char never will have the room for the end of string char to be added to the end of it, so one char variables can never be a string.

Change your data to a string, and try again.

Im not sure how I would go about this. I tried changing my char variables to strings (char data[50]), but I get a lot of errors when compiling.

You changed this?

Code:

struct tnode {
 char data;
 struct tnode *left;
 struct tnode *right;
};

// To:

struct tnode {
 char data[50];
 struct tnode *left;
 struct tnode *right;
};

Any other changes?

I also changed the char tmp to tmp[50] and the %c to %s

This is my latest code, I deleted all the changes I made since it would no longer compile. It should work, make sure you create a p2_input.txt with the format in the picture.

Checking it out with just char's, it has an error, showing 10 items, instead of just 9. You can correct it by changing your while loop for file entry to:

Code:

  while(k!=0){
    j = fscanf(fp, "%d %c", &k, &tmp);
    if(j>1) {                        //stops erroneous entry
      demo_nr[count]=tmp;
      count++;
    }
  }

Outside of that, the char program looks OK to me. Try that new line of code, with your strings.