c++二叉树的创建与遍历并求叶子节点数目完整代码

当然，下面是一个示例的完整代码，用于创建和遍历二叉树，并计算叶子节点数目。

#include <iostream>
using namespace std;

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

// 创建二叉树
TreeNode* createBinaryTree() {
    int val;
    cin >> val;

    if (val == -1) {
        return NULL;
    }

    TreeNode* root = new TreeNode(val);
    cout << "Enter left child of " << val << ": ";
    root->left = createBinaryTree();
    cout << "Enter right child of " << val << ": ";
    root->right = createBinaryTree();

    return root;
}

// 遍历二叉树（前序遍历）
void preOrderTraversal(TreeNode* root) {
    if (root == NULL) {
        return;
    }

    cout << root->val << " ";
    preOrderTraversal(root->left);
    preOrderTraversal(root->right);
}

// 计算叶子节点数目
int countLeafNodes(TreeNode* root) {
    if (root == NULL) {
        return 0;
    }

    if (root->left == NULL && root->right == NULL) {
        return 1;
    }

    return countLeafNodes(root->left) + countLeafNodes(root->right);
}

int main() {
    cout << "Enter root value (-1 for NULL): ";
    TreeNode* root = createBinaryTree();

    cout << "Preorder traversal: ";
    preOrderTraversal(root);
    cout << endl;

    int leafNodeCount = countLeafNodes(root);
    cout << "Number of leaf nodes: " << leafNodeCount << endl;

    return 0;
}

这段代码实现了创建二叉树、前序遍历二叉树以及计算叶子节点数目的功能。你可以根据需要修改或扩展代码。