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

typedef struct _TreeItem {
	struct _TreeItem *left;
	struct _TreeItem *right;
	void *data;
} TreeItem;

void tree_walk_post(TreeItem *item){
	if(item == NULL) return;
	tree_walk_post(item->left);
	tree_walk_post(item->right);
	printf("%s\n", item->data);
}

int main(){
	TreeItem *root;
	TreeItem *cur;

	cur = calloc(1, sizeof(TreeItem));
	cur->data = "data0";
	root = cur;

	cur = calloc(1, sizeof(TreeItem));
	cur->data = "data1";
	root->left = cur;

	cur = calloc(1, sizeof(TreeItem));
	cur->data = "data2";
	root->right = cur;

	cur = calloc(1, sizeof(TreeItem));
	cur->data = "data3";
	root->right->left = cur;

	cur = calloc(1, sizeof(TreeItem));
	cur->data = "data4";
	root->right->right = cur;

	tree_walk_post(root);
}