hello-algo/codes/c/chapter_tree/binary_tree_bfs.c
Yudong Jin 1c8b7ef559
refactor: Replace 结点 with 节点 (#452)
* Replace 结点 with 节点
Update the footnotes in the figures

* Update mindmap

* Reduce the size of the mindmap.png
2023-04-09 04:32:17 +08:00

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1.6 KiB
C++

/**
* File: binary_tree_bfs.c
* Created Time: 2023-01-11
* Author: Reanon (793584285@qq.com)
*/
#include "../include/include.h"
/* 层序遍历 */
int *levelOrder(TreeNode *root, int *size) {
/* 辅助队列 */
int front, rear;
int index, *arr;
TreeNode *node;
TreeNode **queue;
/* 辅助队列 */
queue = (TreeNode **) malloc(sizeof(TreeNode) * MAX_NODE_SIZE);
// 队列指针
front = 0, rear = 0;
// 加入根节点
queue[rear++] = root;
// 初始化一个列表,用于保存遍历序列
/* 辅助数组 */
arr = (int *) malloc(sizeof(int) * MAX_NODE_SIZE);
// 数组指针
index = 0;
while (front < rear) {
// 队列出队
node = queue[front++];
// 保存节点值
arr[index++] = node->val;
if (node->left != NULL) {
// 左子节点入队
queue[rear++] = node->left;
}
if (node->right != NULL) {
// 右子节点入队
queue[rear++] = node->right;
}
}
// 更新数组长度的值
*size = index;
arr = realloc(arr, sizeof(int) * (*size));
return arr;
}
/* Driver Code */
int main() {
/* 初始化二叉树 */
// 这里借助了一个从数组直接生成二叉树的函数
int nums[] = {1, 2, 3, NIL, 5, 6, NIL};
int size = sizeof(nums) / sizeof(int);
TreeNode *root = arrToTree(nums, size);
printf("初始化二叉树\n");
printTree(root);
/* 层序遍历 */
// 需要传入数组的长度
int *arr = levelOrder(root, &size);
printf("层序遍历的节点打印序列 = ");
printArray(arr, size);
return 0;
}