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tree.c
187 lines (148 loc) · 4.05 KB
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tree.c
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#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include "items.h"
#include "tree.h"
typedef struct treenode {
item_t *item;
struct treenode *left;
struct treenode *right;
} treenode_t;
typedef struct tree{
treenode_t *root;
} tree_t;
tree_t *tree_new(){
tree_t *emptytree = NULL;
emptytree = calloc(1, sizeof(tree_t));
return emptytree;
}
int tree_size(treenode_t *tree)
{
int i = 1;
if (tree == NULL)
return 0;
else {
i += tree_size(tree->left);
i += tree_size(tree->right);
return i;
}
}
treenode_t *minimum_Node(treenode_t *treenode){
while (treenode->left != NULL){
treenode = treenode->left;
}
return treenode;
}
int max_depth(treenode_t *tree){
int leftDepth;
int rightDepth;
if (tree == NULL) return 0;
else
{
leftDepth = max_depth(tree->left);
rightDepth = max_depth(tree->right);
if (leftDepth > rightDepth)
return (leftDepth + 1);
else return (rightDepth + 1);
}
}
treenode_t* find_node(treenode_t *treenode, char *name){
if(treenode == NULL){
return NULL;
}
else if (strcmp(name, itemname(treenode->item)) == 0){
return treenode;
}
else if(strcmp(name, itemname(treenode->item)) > 0){
return find_node(treenode->right, name);
}
else{
return find_node(treenode->left, name);
}
}
treenode_t* inorder_successor(treenode_t *treenode, char *name){
treenode_t *current = find_node(treenode, name);
if (current == NULL){
return NULL;
}
//case 1: node has right subtree//
if ((current->right) != NULL){
return minimum_Node(current->right);
}
// case 2: no right subtree //
else {
treenode_t *successor = NULL;
treenode_t *ancestor = treenode;
while(ancestor != current){
if (strcmp ((itemname(current->item)), (itemname(ancestor->item))) < 0){
successor = ancestor;
ancestor = ancestor->left;
}
else ancestor = ancestor->right;
}
return successor;
}
}
treenode_t* tree_remove(treenode_t **treenode, char *name){
if (*treenode == NULL){
return *treenode;
}
if(strcmp(name, itemname((*treenode)->item)) < 0){
(*treenode)->left = tree_remove(&(*treenode)->left, name);
}
if (strcmp(name, itemname((*treenode)->item)) > 0){
(*treenode)->right = tree_remove(&(*treenode)->right, name);
}
else if ((*treenode)->left == NULL && (*treenode)->right == NULL){
free(treenode);
}
/// Node has 1 child (right)
else if ((*treenode)->left == NULL) {
treenode_t *temp = (*treenode)->right;
free(*treenode);
return temp;
}
/// Node has 1 child (left)
else if ((*treenode)->right == NULL){
treenode_t*temp = (*treenode) ->left;
free(*treenode);
return temp;
}
// Find inorder successor
treenode_t *temp = inorder_successor((*treenode)->right, name);
//store inorder successor in node
(*treenode)->item = temp->item;
//delete the inorder successor
(*treenode)->right = tree_remove(&(*treenode)->right, itemname(temp->item));
return *treenode;
}
treenode_t *create_treenode(item_t *item){
treenode_t *temp;
temp = calloc(1, sizeof(treenode_t));
temp->item = item;
temp->left = temp->right = NULL;
return temp;
}
treenode_t* tree_insert(treenode_t **treenode, item_t *item){
if (treenode == NULL){
(*treenode) = create_treenode(item);
return 0; // Not sure it should return 0..
//(just so it compiles for now)
}
else if(strcmp(itemname(item), itemname((*treenode)->item)) < 0)
(*treenode)->left= tree_insert(&(*treenode)->left , item);
else if(strcmp(itemname(item), itemname((*treenode)->item)) == 0)
(*treenode)->left= tree_insert(&(*treenode)->left , item);
else (*treenode)->right = tree_insert(&(*treenode)->right, item);
return *treenode;
}
void ordered_print(treenode_t *treenode){
if(treenode == NULL){
puts("No more items to print");
return;
}
ordered_print(treenode->left);
printf("%s", itemname(treenode->item));
ordered_print(treenode->right);
}