二叉树两点最短距离 C++

以下是使用C++编写的二叉树两点最短距离的代码示例：

#include <iostream>
#include <queue>

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

// 寻找最低公共祖先节点
TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
    if (root == nullptr || root == p || root == q) {
        return root;
    }
    
    TreeNode* left = lowestCommonAncestor(root->left, p, q);
    TreeNode* right = lowestCommonAncestor(root->right, p, q);
    
    if (left && right) {
        return root;
    } else if (left) {
        return left;
    } else {
        return right;
    }
}

// 计算节点到最低公共祖先节点的距离
int distanceToLCA(TreeNode* node, TreeNode* target) {
    if (node == nullptr) {
        return INT_MAX;
    }
    
    if (node == target) {
        return 0;
    }
    
    return 1 + std::min(distanceToLCA(node->left, target), distanceToLCA(node->right, target));
}

// 计算最短距离
int shortestDistance(TreeNode* root, TreeNode* p, TreeNode* q) {
    TreeNode* lca = lowestCommonAncestor(root, p, q);
    
    int distance_p = distanceToLCA(lca, p);
    int distance_q = distanceToLCA(lca, q);
    
    return distance_p + distance_q;
}

int main() {
    // 创建二叉树
    TreeNode* root = new TreeNode(3);
    root->left = new TreeNode(5);
    root->right = new TreeNode(1);
    root->left->left = new TreeNode(6);
    root->left->right = new TreeNode(2);
    root->right->left = new TreeNode(0);
    root->right->right = new TreeNode(8);
    root->left->right->left = new TreeNode(7);
    root->left->right->right = new TreeNode(4);

    // 寻找节点5和节点4的最短距离
    int distance = shortestDistance(root, root->left, root->left->right->right);
    std::cout << distance << std::endl;  // 输出2，即节点5和节点4之间的最短距离

    return 0;
}

请注意，此示例代码中使用了C++标准库的queue和iostream头文件，并假设了树中的节点值不重复。在实际应用中，你可能需要根据具体情况进行调整。