请你用c++编写程序对二叉树进行遍历，要求实现递归前序、中序、后序遍历和非递归前序、中序、后序遍历

好的，我可以为您提供 C++ 的代码实现。以下是对二叉树的前序、中序、后序递归遍历和前序、中序、后序非递归遍历的实现：

#include <iostream>
#include <stack>

using namespace std;

// 定义二叉树节点
struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x): val(x), left(nullptr), right(nullptr) {}
};

// 递归前序遍历
void preOrderTraversalRecursion(TreeNode* root) {
    if(root == nullptr) {
        return;
    }
    cout << root->val << " ";
    preOrderTraversalRecursion(root->left);
    preOrderTraversalRecursion(root->right);
}

// 递归中序遍历
void inOrderTraversalRecursion(TreeNode* root) {
    if(root == nullptr) {
        return;
    }
    inOrderTraversalRecursion(root->left);
    cout << root->val << " ";
    inOrderTraversalRecursion(root->right);
}

// 递归后序遍历
void postOrderTraversalRecursion(TreeNode* root) {
    if(root == nullptr) {
        return;
    }
    postOrderTraversalRecursion(root->left);
    postOrderTraversalRecursion(root->right);
    cout << root->val << " ";
}

// 非递归前序遍历
void preOrderTraversalIterative(TreeNode* root) {
    stack<TreeNode*> st;
    if(root != nullptr) {
        st.push(root);
    }
    while(!st.empty()) {
        TreeNode* node = st.top();
        st.pop();
        cout << node->val << " ";
        if(node->right != nullptr) {
            st.push(node->right);
        }
        if(node->left != nullptr) {
            st.push(node->left);
        }
    }
}

// 非递归中序遍历
void inOrderTraversalIterative(TreeNode* root) {
    stack<TreeNode*> st;
    TreeNode* node = root;
    while(node != nullptr || !st.empty()) {
        while(node != nullptr) {
            st.push(node);
            node = node->left;
        }
        node = st.top();
        st.pop();
        cout << node->val << " ";
        node = node->right;
    }
}

// 非递归后序遍历
void postOrderTraversalIterative(TreeNode* root) {
    stack<TreeNode*> st;
    TreeNode* node = root;
    TreeNode* lastVisited = nullptr;
    while(node != nullptr || !st.empty()) {
        while(node != nullptr) {
            st.push(node);
            node = node->left;
        }
        node = st.top();
        if(node->right == nullptr || node->right == lastVisited) {
            st.pop();
            cout << node->val << " ";
            lastVisited = node;
            node = nullptr;
        } else {
            node = node->right;
        }
    }
}

int main() {
    // 创建二叉树
    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);

    // 递归遍历二叉树
    cout << "递归前序遍历：";
    preOrderTraversalRecursion(root);
    cout << endl;

    cout << "递归中序遍历：";
    inOrderTraversalRecursion(root);
    cout << endl;

    cout << "递归后序遍历：";
    postOrderTraversalRecursion(root);
    cout << endl;

    // 非递归遍历二叉树
    cout << "非递归前序遍历：";
    preOrderTraversalIterative(root);
    cout << endl;

    cout << "非递归中序遍历：";
    inOrderTraversalIterative(root);
    cout << endl;

    cout << "非递归后序遍历：";
    postOrderTraversalIterative(root);
    cout << endl;

    return 0;
}

上述代码实现了二叉树的递归和非递归前序、中序和后序遍历。其中，递归遍历使用了函数递归调用，非递归遍历则使用了栈结构来模拟递归过程。我们可以通过构造二叉树并调用上述遍历函数来测试代码的正确性。