在c++中遍历通用树

struct TreeNode {
    int val;
    vector<TreeNode*> children;
};

void traverse(TreeNode* root) {
    if (root == nullptr) {
        return;
    }
    
    // 前序遍历
    cout << root->val << " ";
    
    for (TreeNode* child : root->children) {
        traverse(child);
    }
    
    // 后序遍历
    // cout << root->val << " ";
}

int main() {
    // 构建通用树
    TreeNode* root = new TreeNode{1, {
        new TreeNode{2, {
            new TreeNode{5, {}},
            new TreeNode{6, {}}
        }},
        new TreeNode{3, {}},
        new TreeNode{4, {}}
    }};
    
    // 遍历通用树
    traverse(root);
    
    return 0;
}

struct TreeNode {
    int val;
    vector<TreeNode*> children;
};

void traverse(TreeNode* root) {
    if (root == nullptr) {
        return;
    }
    
    stack<TreeNode*> stk;
    stk.push(root);
    
    while (!stk.empty()) {
        TreeNode* node = stk.top();
        stk.pop();
        
        // 前序遍历
        cout << node->val << " ";
        
        // 将子节点逆序入栈
        for (int i = node->children.size() - 1; i >= 0; i--) {
            stk.push(node->children[i]);
        }
        
        // 后序遍历
        // cout << node->val << " ";
    }
}

int main() {
    // 构建通用树
    TreeNode* root = new TreeNode{1, {
        new TreeNode{2, {
            new TreeNode{5, {}},
            new TreeNode{6, {}}
        }},
        new TreeNode{3, {}},
        new TreeNode{4, {}}
    }};
    
    // 遍历通用树
    traverse(root);
    
    return 0;
}