algo/c-cpp/23_binarytree/binarytree.c
2018-11-12 10:08:38 +08:00

84 lines
1.2 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <time.h>
/* Implement binary tree in array */
#define MAX_TREE_NODES (1 << 8)
struct node {
int data;
};
struct binary_tree {
union {
unsigned long nodes;
struct node *n[MAX_TREE_NODES];
};
};
void init_binary_tree(struct binary_tree *tree)
{
int i;
for(i = 0; i < MAX_TREE_NODES; i++) {
tree->n[i] = NULL;
}
}
struct node* create_node(int data)
{
struct node* n;
n = malloc(sizeof(struct node));
if (n)
n->data = data;
return n;
}
void fake_a_tree(struct binary_tree* tree)
{
/* data is in ordered */
int i, data[10] = {7, 4, 9, 2, 6, 8, 10, 1, 3, 5};
init_binary_tree(tree);
/* root start at 1 */
for (i = 0; i < 10; i++)
tree->n[i+1] = create_node(data[i]);
tree->nodes = 10;
}
void _in_order(struct binary_tree* tree, int index)
{
if (!tree->n[index])
return;
/* left child at (index << 1) */
_in_order(tree, index << 1);
printf("[%2d]: %4d\n", index, tree->n[index]->data);
/* right child at (index << 1) + 1 */
_in_order(tree, (index << 1) + 1);
}
void in_order(struct binary_tree* tree)
{
_in_order(tree, 1);
}
int main()
{
struct binary_tree tree;
fake_a_tree(&tree);
in_order(&tree);
return 0;
}