Thread: Count occurrence in bin tree

I need to count the number of times a certain char has performed in a
string.
Means to the string:
cefgacaffe

output:
char occurence
a 2
c 2
e 2
f 3
g 1

This is what I've been up to:

Code:

#include<stdio.h>
#include<malloc.h>

typedef struct tree_el {
   char data;
   int counter;
   struct tree_el * right, * left;
}TREE;

typedef TREE *node;

void insert(node * tree, node* item)
{
	if(!(*tree)) {
	*tree = *item;
	return;
	}
	if((*item)->data<(*tree)->data)
		insert(&(*tree)->left, item);
	else if((*item)->data>(*tree)->data)
		insert(&(*tree)->right, item);
}

char intrav (node tree, char data)
{
	if (tree!=NULL)
	{
		
		if (intrav(tree->left, data)==data)
			++(tree->counter);		
		printf ("%c | %d\n", tree->data, tree->counter);
		intrav(tree->right, data);
	}
	return data;
}

void CountOcrnc (node tree)
{
	node temp;
	temp=(node)malloc(sizeof(node));
	temp->left= temp->right= NULL;
	temp=tree;
	while (tree!=NULL) 
	{
		intrav(tree, temp->data);
		tree=tree->left;
		tree=tree->right;
	}
}

int main(void)
{
	char ltrs[20]={"cefgacaffe0"};
int count=0;
node curr=NULL, root= NULL;
while ( ltrs[count] != '0' )
	{
		curr=(node) malloc (sizeof (TREE));
		curr->left= curr->right= NULL;
		curr->counter=0;
		curr->data=ltrs[count];
		insert(&root, &curr);
		++count;
	}

CountOcrnc (root);
   return 1;
}

Guess I don't get expected output, cause of a mass I'm facing in intrav function.
Please help me organize it.

TIA,

Ronen

In insert, if the node is found, increment counter. If the node is not found, set counter to 1. Now, to print each letter with the number of occurances, you just need to traverse the tree.

Code:

#include<stdio.h>
#include<stdlib.h> /* malloc.h is not standard */

typedef struct tree_el {
    char data;
    int counter;
    struct tree_el * right, * left;
}TREE;

typedef TREE *node;

void insert(node * tree, node* item)
{
    if(!(*tree)) {
        *tree = *item;
        return;
    }
    if((*item)->data<(*tree)->data)
        insert(&(*tree)->left, item);
    else if((*item)->data>(*tree)->data)
        insert(&(*tree)->right, item);
    else
        ++(*tree)->counter;
}

void intrav (node tree)
{
    if (tree!=NULL)
    {
        intrav(tree->left);	
        printf ("%c | %d\n", tree->data, tree->counter);
        intrav(tree->right);
    }
}

int main(void)
{
    char ltrs[20]={"cefgacaffe0"};
    int count=0;

    node curr=NULL, root= NULL;
    while ( ltrs[count] != '0' )
    {
        curr=(node) malloc (sizeof (TREE));
        curr->left= curr->right= NULL;
        curr->counter=1;
        curr->data=ltrs[count];
        insert(&root, &curr);
        ++count;
    }
    intrav(root);

    return 0; /* 0 is success, nonzero is failure */
}

Thank you, Ren!