判断完全二叉树c语言

可以使用层序遍历的方法来判断一棵二叉树是否为完全二叉树。具体实现可以参考以下C语言代码：

#include <stdio.h>
#include <stdlib.h>

// 定义二叉树结点
typedef struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
} TreeNode;

// 定义队列结点
typedef struct QueueNode {
    TreeNode *node;
    struct QueueNode *next;
} QueueNode;

// 定义队列
typedef struct Queue {
    QueueNode *front;
    QueueNode *rear;
} Queue;

// 初始化队列
void initQueue(Queue *queue) {
    queue->front = NULL;
    queue->rear = NULL;
}

// 入队
void enqueue(Queue *queue, TreeNode *node) {
    QueueNode *newNode = (QueueNode *)malloc(sizeof(QueueNode));
    newNode->node = node;
    newNode->next = NULL;
    if (queue->rear == NULL) {
        queue->front = newNode;
        queue->rear = newNode;
    } else {
        queue->rear->next = newNode;
        queue->rear = newNode;
    }
}

// 出队
TreeNode *dequeue(Queue *queue) {
    if (queue->front == NULL) {
        return NULL;
    }
    TreeNode *node = queue->front->node;
    QueueNode *temp = queue->front;
    queue->front = queue->front->next;
    if (queue->front == NULL) {
        queue->rear = NULL;
    }
    free(temp);
    return node;}

// 判断是否为完全二叉树
int isCompleteTree(TreeNode *root) {
    if (root == NULL) {
        return 1;
    }
    Queue queue;
    initQueue(&queue);
    enqueue(&queue, root);
    int flag = 0;
    while (queue.front != NULL) {
        TreeNode *node = dequeue(&queue);
        if (node == NULL) {
            flag = 1;
        } else {
            if (flag) {
                return 0;
            }
            enqueue(&queue, node->left);
            enqueue(&queue, node->right);
        }
    }
    return 1;
}