用c语言写一个完全二叉树

以下是用C语言实现完全二叉树的代码，其中包括创建完全二叉树、层次遍历以及判断是否为完全二叉树的函数：

#include <stdio.h>
#include <stdlib.h>
#define MAXSIZE 100

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

// 定义队列结构体
typedef struct Queue {
    TreeNode *data[MAXSIZE];
    int front, rear;
} Queue;

// 初始化队列
void initQueue(Queue *q) {
    q->front = q->rear = 0;
}

// 判断队列是否为空
int isEmpty(Queue *q) {
    return q->front == q->rear;
}

// 入队
void enQueue(Queue *q, TreeNode *node) {
    if ((q->rear + 1) % MAXSIZE == q->front) {
        printf("Queue is full.\n");
        return;
    }
    q->data[q->rear] = node;
    q->rear = (q->rear + 1) % MAXSIZE;
}

// 出队
TreeNode *deQueue(Queue *q) {
    if (isEmpty(q)) {
        printf("Queue is empty.\n");
        return NULL;
    }
    TreeNode *node = q->data[q->front];
    q->front = (q->front + 1) % MAXSIZE;
    return node;
}

// 创建完全二叉树
TreeNode *createCompleteBinaryTree(int *arr, int size, int index) {
    if (index >= size) {
        return NULL;
    }
    TreeNode *root = (TreeNode *)malloc(sizeof(TreeNode));
    root->data = arr[index];
    root->left = createCompleteBinaryTree(arr, size, 2 * index + 1);
    root->right = createCompleteBinaryTree(arr, size, 2 * index + 2);
    return root;
}

// 层次遍历
void levelOrderTraversal(TreeNode *root) {
    if (root == NULL) {
        return;
    }
    Queue q;
    initQueue(&q);
    enQueue(&q, root);
    while (!isEmpty(&q)) {
        TreeNode *node = deQueue(&q);
        printf("%d ", node->data);
        if (node->left != NULL) {
            enQueue(&q, node->left);
        }
        if (node->right != NULL) {
            enQueue(&q, node->right);
        }
    }
}

// 判断是否为完全二叉树
int isCompleteBinaryTree(TreeNode *root) {
    if (root == NULL) {
        return 1;
    }
    Queue q;
    initQueue(&q);
    enQueue(&q, root);
    int flag = 0;
    while (!isEmpty(&q)) {
        TreeNode *node = deQueue(&q);
        if (node == NULL) {
            flag = 1;
        } else {
            if (flag == 1) {
                return 0;
            }
            enQueue(&q, node->left);
            enQueue(&q, node->right);
        }
    }
    return 1;
}

int main() {
    int arr[] = {1, 2, 3, 4, 5, 6, 7};
    int size = sizeof(arr) / sizeof(arr[0]);
    TreeNode *root = createCompleteBinaryTree(arr, size, 0);
    printf("层次遍历结果为：");
    levelOrderTraversal(root);
    printf("\n");
    if (isCompleteBinaryTree(root)) {
        printf("该二叉树是完全二叉树。\n");
    } else {
        printf("该二叉树不是完全二叉树。\n");
    }
    return 0;
}