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.

Quote:

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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;
}

---

;)

Quote:

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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