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108 lines
2.5 KiB
C
108 lines
2.5 KiB
C
/**
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* File: tree_node.h
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* Created Time: 2023-01-09
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* Author: Reanon (793584285@qq.com)
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*/
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#ifndef TREE_NODE_H
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#define TREE_NODE_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <limits.h>
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#define MAX_NODE_SIZE 5000
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/* 二叉树节点结构体 */
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typedef struct TreeNode {
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int val; // 节点值
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int height; // 节点高度
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struct TreeNode *left; // 左子节点指针
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struct TreeNode *right; // 右子节点指针
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} TreeNode;
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/* 构造函数 */
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TreeNode *newTreeNode(int val) {
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TreeNode *node;
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node = (TreeNode *)malloc(sizeof(TreeNode));
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node->val = val;
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node->height = 0;
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node->left = NULL;
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node->right = NULL;
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return node;
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}
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// 序列化编码规则请参考：
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// https://www.hello-algo.com/chapter_tree/array_representation_of_tree/
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// 二叉树的数组表示：
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// [1, 2, 3, 4, None, 6, 7, 8, 9, None, None, 12, None, None, 15]
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// 二叉树的链表表示：
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// /——— 15
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// /——— 7
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// /——— 3
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// | \——— 6
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// | \——— 12
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// ——— 1
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// \——— 2
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// | /——— 9
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// \——— 4
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// \——— 8
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/* 将列表反序列化为二叉树：递归 */
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TreeNode *arrayToTreeDFS(int *arr, int size, int i) {
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if (i < 0 || i >= size || arr[i] == INT_MAX) {
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return NULL;
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}
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TreeNode *root = (TreeNode *)malloc(sizeof(TreeNode));
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root->val = arr[i];
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root->left = arrayToTreeDFS(arr, size, 2 * i + 1);
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root->right = arrayToTreeDFS(arr, size, 2 * i + 2);
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return root;
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}
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/* 将列表反序列化为二叉树 */
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TreeNode *arrayToTree(int *arr, int size) {
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return arrayToTreeDFS(arr, size, 0);
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}
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/* 将二叉树序列化为列表：递归 */
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void treeToArrayDFS(TreeNode *root, int i, int *res, int *size) {
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if (root == NULL) {
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return;
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}
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while (i >= *size) {
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res = realloc(res, (*size + 1) * sizeof(int));
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res[*size] = INT_MAX;
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(*size)++;
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}
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res[i] = root->val;
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treeToArrayDFS(root->left, 2 * i + 1, res, size);
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treeToArrayDFS(root->right, 2 * i + 2, res, size);
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}
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/* 将二叉树序列化为列表 */
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int *treeToArray(TreeNode *root, int *size) {
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*size = 0;
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int *res = NULL;
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treeToArrayDFS(root, 0, res, size);
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return res;
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}
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/* 释放二叉树内存 */
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void freeMemoryTree(TreeNode *root) {
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if (root == NULL)
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return;
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freeMemoryTree(root->left);
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freeMemoryTree(root->right);
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free(root);
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}
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#ifdef __cplusplus
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}
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#endif
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#endif // TREE_NODE_H
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