C++用递归和非递归求叶子数的主函数的源代码

好的，以下是 C++ 的源代码：

1. 递归方法：

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

int countLeaves_recursive(TreeNode* root) {
    if (!root) {
        return 0;
    }
    if (!root->left && !root->right) {
        return 1;
    }
    return countLeaves_recursive(root->left) + countLeaves_recursive(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 leaves = countLeaves_recursive(root);
    cout << "The number of leaves is: " << leaves << endl;

    return 0;
}

2. 非递归方法：

int countLeaves_iterative(TreeNode* root) {
    if (!root) {
        return 0;
    }
    stack<TreeNode*> s;
    s.push(root);
    int count = 0;
    while (!s.empty()) {
        TreeNode* node = s.top();
        s.pop();
        if (!node->left && !node->right) {
            count++;
        } else {
            if (node->left) {
                s.push(node->left);
            }
            if (node->right) {
                s.push(node->right);
            }
        }
    }
    return count;
}

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 leaves = countLeaves_iterative(root);
    cout << "The number of leaves is: " << leaves << endl;

    return 0;
}

希望这些代码能够帮助到你！