retrieving a value from nested struct gives negative values

Code:

/*
 * treeattempt1.c
 *
 *  Created on: 21/06/2012
 *      Author: logan
 */

#include <stdio.h>

struct node {
	int value;
	struct element* elements;
};

struct element {
	struct node* child_node;
};

int numbers[3]={1,2,3};

int main() {
	// create a tree with three branches
	struct element branches[3];
	struct node tree;
	tree.elements=&branches[0];

	// before we populate tree we need to point each child nodes to root of the tree
	struct node childs[3];
	int m=0;
	for (m=0; m<3; m++) {
		tree.elements[m].child_node=&childs[m];
	}

	// fill tree with numbers 1, 2, 3
	int i=0;
	for (i=0; i<3; i++) {
		tree.elements[i].child_node->value=numbers[i];
	}

	// try printing out values in the tree
	int j=0;
	for (j=0; j<3; j++) {
		printf("%d", tree.elements[i].child_node->value);
	}
	return 0;
}

This gives three negative values when I expect values 1, 2, 3. Any help will be appreciated!

That's one wacky data structure you've created there. Your error, besides the general insanity, is using i instead of j in your printf.

Originally Posted by oogabooga

That's one wacky data structure you've created there. Your error, besides the general insanity, is using i instead of j in your printf.

Thanks man. Don't call me wacko though. I was trying to create a tree like structure.

Fixing that small error it prints 123.

Code:

/*
 * treeattempt1.h
 *
 *  Created on: 21/06/2012
 *      Author: logan
 */

#ifndef TREEATTEMPT1_H_
#define TREEATTEMPT1_H_


#endif /* TREEATTEMPT1_H_ */

struct node {
	int value;
	struct element* elements;
};

struct element {
	struct node* child_node;
};

Code:

/*
 * treeattempt1.c
 *
 *  Created on: 21/06/2012
 *      Author: logan
 */

#include <stdio.h>
#include "treeattempt1.h"

int numbers[3]={1,2,3};

int main() {
	// create a tree with three branches
	struct element branches[3];
	struct node tree;
	tree.elements=&branches[0];

	// before we populate tree we need to point each child nodes to root of the tree
	struct node childs[3];
	int m=0;
	for (m=0; m<3; m++) {
		tree.elements[m].child_node=&childs[m];
	}

	// fill tree with numbers 1, 2, 3
	int i=0;
	for (i=0; i<3; i++) {
		tree.elements[i].child_node->value=numbers[i];
	}

	// try printing out values in the tree
	int j=0;
	for (j=0; j<3; j++) {
		printf("%d", tree.elements[j].child_node->value);
	}

	return 0;
}

Originally Posted by gunitinug

Don't call me wacko though. I was trying to create a tree like structure.

Calm down. He didn't call you a wacko. He called your data structure wacky and imho he is right.

Code:

/*
 * treeattempt1.h
 *
 *  Created on: 21/06/2012
 *      Author: logan
 */

#ifndef TREEATTEMPT1_H_
#define TREEATTEMPT1_H_


#endif /* TREEATTEMPT1_H_ */

struct node {
    int value;
    struct element* elements;
};

struct element {
    struct node* child_node;
};

If you want to avoid including your header more than once in a program, your method doesn't work. You have to put the whole code inside the #ifndef and #endif block.

Bye, Andreas