cpp-algo-cases/chapter_backtracking/preorder_traversal_iii_comp...

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C++

/**
* File: preorder_traversal_iii_compact.cpp
* Created Time: 2023-04-16
* Author: krahets (krahets@163.com)
*/
#include "../utils/common.hpp"
vector<TreeNode *> path;
vector<vector<TreeNode *>> res;
/* 前序遍历:例题三 */
void preOrder(TreeNode *root) {
// 剪枝
if (root == nullptr || root->val == 3) {
return;
}
// 尝试
path.push_back(root);
if (root->val == 7) {
// 记录解
res.push_back(path);
}
preOrder(root->left);
preOrder(root->right);
// 回退
path.pop_back();
}
/* Driver Code */
int main() {
TreeNode *root = vectorToTree(vector<int>{1, 7, 3, 4, 5, 6, 7});
cout << "\n初始化二叉树" << endl;
printTree(root);
// 前序遍历
preOrder(root);
cout << "\n输出所有根节点到节点 7 的路径,要求路径中不包含值为 3 的节点" << endl;
for (vector<TreeNode *> &path : res) {
vector<int> vals;
for (TreeNode *node : path) {
vals.push_back(node->val);
}
printVector(vals);
}
}