给定一颗二叉树，要求输出遍历该二叉树得到的先序、中序、后序遍历序列。C语言代码

以下是 C 语言代码实现二叉树的先序、中序、后序遍历：

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

struct Node {
    int data;
    struct Node *left;
    struct Node *right;
};

struct Node* newNode(int data) {
    struct Node* node = (struct Node*)malloc(sizeof(struct Node));
    node->data = data;
    node->left = NULL;
    node->right = NULL;
    return node;
}

void preOrder(struct Node* node) {
    if (node == NULL) return;
    printf("%d ", node->data);
    preOrder(node->left);
    preOrder(node->right);
}

void inOrder(struct Node* node) {
    if (node == NULL) return;
    inOrder(node->left);
    printf("%d ", node->data);
    inOrder(node->right);
}

void postOrder(struct Node* node) {
    if (node == NULL) return;
    postOrder(node->left);
    postOrder(node->right);
    printf("%d ", node->data);
}

int main() {
    struct Node* root = newNode(1);
    root->left = newNode(2);
    root->right = newNode(3);
    root->left->left = newNode(4);
    root->left->right = newNode(5);
    printf("Preorder traversal: ");
    preOrder(root);
    printf("\nInorder traversal: ");
    inOrder(root);
    printf("\nPostorder traversal: ");
    postOrder(root);
    return 0;
}

输出结果为：

Preorder traversal: 1 2 4 5 3 
Inorder traversal: 4 2 5 1 3 
Postorder traversal: 4 5 2 3 1