c++ 中求二叉树中度为2的结点以及叶子结点的数目

求二叉树中度为2的结点数目：

int countTwoDegreeNode(TreeNode* root) {
    if (root == NULL) {
        return 0;
    }
    if (root->left != NULL && root->right != NULL) {
        return countTwoDegreeNode(root->left) + countTwoDegreeNode(root->right) + 1;
    } else {
        return countTwoDegreeNode(root->left) + countTwoDegreeNode(root->right);
    }
}

求二叉树中叶子结点数目：

int countLeafNode(TreeNode* root) {
    if (root == NULL) {
        return 0;
    }
    if (root->left == NULL && root->right == NULL) {
        return 1;
    } else {
        return countLeafNode(root->left) + countLeafNode(root->right);
    }
}

相关问题

写代码,用c++先用先序遍历构建二叉树，再求二叉树的叶子结点数目和度为二的结点数目

以下是代码实现：

#include <iostream>
using namespace std;

struct TreeNode {
    char val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(char x) : val(x), left(nullptr), right(nullptr) {}
};

// 构建二叉树，输入先序遍历序列
TreeNode* buildTree() {
    char ch;
    cin >> ch;
    if (ch == '#') {
        return nullptr;
    }
    TreeNode* root = new TreeNode(ch);
    root->left = buildTree();
    root->right = buildTree();
    return root;
}

// 计算二叉树叶子节点数目和度为二的节点数目
void count(TreeNode* root, int& leafCount, int& degree2Count) {
    if (!root) {
        return;
    }
    if (!root->left && !root->right) {
        leafCount++;
    } else if (root->left && root->right) {
        degree2Count++;
    }
    count(root->left, leafCount, degree2Count);
    count(root->right, leafCount, degree2Count);
}

int main() {
    TreeNode* root = buildTree();
    int leafCount = 0;
    int degree2Count = 0;
    count(root, leafCount, degree2Count);
    cout << "叶子节点数目：" << leafCount << endl;
    cout << "度为二的节点数目：" << degree2Count << endl;
    return 0;
}

输入示例：

AB#D##CE##F##

输出结果：

叶子节点数目：3
度为二的节点数目：2

c++编程实现：求二叉树的高度和叶子结点个数

#include <iostream>
using namespace std;

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

int getHeight(TreeNode* root) {
if (root == NULL) return 0;
int leftHeight = getHeight(root->left);
int rightHeight = getHeight(root->right);
return max(leftHeight, rightHeight) + 1;
}

int getLeafCount(TreeNode* root) {
if (root == NULL) return 0;
if (root->left == NULL && root->right == NULL) return 1;
return getLeafCount(root->left) + getLeafCount(root->right);
}

int main() {
TreeNode* root = new TreeNode(1);
root->left = new TreeNode(2);
root->right = new TreeNode(3);
root->left->left = new TreeNode(4);
root->left->right = new TreeNode(5);
root->right->left = new TreeNode(6);
root->right->right = new TreeNode(7);

int height = getHeight(root);
int leafCount = getLeafCount(root);

cout << "The height of the binary tree is: " << height << endl;
cout << "The number of leaf nodes in the binary tree is: " << leafCount << endl;

return 0;
}