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hello-algo/zh-hant/codes/c/utils/tree_node.h

108 lines
2.5 KiB

/**
* File: tree_node.h
* Created Time: 2023-01-09
* Author: Reanon (793584285@qq.com)
*/
#ifndef TREE_NODE_H
#define TREE_NODE_H
#ifdef __cplusplus
extern "C" {
#endif
#include <limits.h>
#define MAX_NODE_SIZE 5000
/* 二元樹節點結構體 */
typedef struct TreeNode {
int val; // 節點值
int height; // 節點高度
struct TreeNode *left; // 左子節點指標
struct TreeNode *right; // 右子節點指標
} TreeNode;
/* 建構子 */
TreeNode *newTreeNode(int val) {
TreeNode *node;
node = (TreeNode *)malloc(sizeof(TreeNode));
node->val = val;
node->height = 0;
node->left = NULL;
node->right = NULL;
return node;
}
// 序列化編碼規則請參考:
// https://www.hello-algo.com/chapter_tree/array_representation_of_tree/
// 二元樹的陣列表示:
// [1, 2, 3, 4, None, 6, 7, 8, 9, None, None, 12, None, None, 15]
// 二元樹的鏈結串列表示:
// /——— 15
// /——— 7
// /——— 3
// | \——— 6
// | \——— 12
// ——— 1
// \——— 2
// | /——— 9
// \——— 4
// \——— 8
/* 將串列反序列化為二元樹:遞迴 */
TreeNode *arrayToTreeDFS(int *arr, int size, int i) {
if (i < 0 || i >= size || arr[i] == INT_MAX) {
return NULL;
}
TreeNode *root = (TreeNode *)malloc(sizeof(TreeNode));
root->val = arr[i];
root->left = arrayToTreeDFS(arr, size, 2 * i + 1);
root->right = arrayToTreeDFS(arr, size, 2 * i + 2);
return root;
}
/* 將串列反序列化為二元樹 */
TreeNode *arrayToTree(int *arr, int size) {
return arrayToTreeDFS(arr, size, 0);
}
/* 將二元樹序列化為串列:遞迴 */
void treeToArrayDFS(TreeNode *root, int i, int *res, int *size) {
if (root == NULL) {
return;
}
while (i >= *size) {
res = realloc(res, (*size + 1) * sizeof(int));
res[*size] = INT_MAX;
(*size)++;
}
res[i] = root->val;
treeToArrayDFS(root->left, 2 * i + 1, res, size);
treeToArrayDFS(root->right, 2 * i + 2, res, size);
}
/* 將二元樹序列化為串列 */
int *treeToArray(TreeNode *root, int *size) {
*size = 0;
int *res = NULL;
treeToArrayDFS(root, 0, res, size);
return res;
}
/* 釋放二元樹記憶體 */
void freeMemoryTree(TreeNode *root) {
if (root == NULL)
return;
freeMemoryTree(root->left);
freeMemoryTree(root->right);
free(root);
}
#ifdef __cplusplus
}
#endif
#endif // TREE_NODE_H