/** * File: preorder_traversal_ii_compact.c * Created Time: 2023-05-28 * Author: Gonglja (glj0@outlook.com) */ #include "../utils/common.h" /* 前序遍历:例题二 */ void preOrder(TreeNode *root, vector *path, vector *res) { if (root == NULL) { return; } // 尝试 vectorPushback(path, root, sizeof(TreeNode)); if (root->val == 7) { // 记录解 vector *newPath = newVector(); for (int i = 0; i < path->size; i++) { vectorPushback(newPath, path->data[i], sizeof(int)); } vectorPushback(res, newPath, sizeof(vector)); } preOrder(root->left, path, res); preOrder(root->right, path, res); // 回退 vectorPopback(path); } // 打印向量中的元素 void printResult(vector *vv) { for (int i = 0; i < vv->size; i++) { vector *v = (vector *)vv->data[i]; for (int j = 0; j < v->size; j++) { TreeNode *node = (TreeNode *)v->data[j]; printf("%d ", node->val); } printf("\n"); } } /* Driver Code */ int main() { int arr[] = {1, 7, 3, 4, 5, 6, 7}; int n = sizeof(arr) / sizeof(arr[0]); TreeNode *root = arrToTree(arr, n); printf("\r\n初始化二叉树\r\n"); printTree(root); // 创建存储路径和结果的向量 vector *path = newVector(); vector *res = newVector(); // 前序遍历 preOrder(root, path, res); // 输出结果 printf("输出所有根节点到节点 7 的路径:\n"); printResult(res); // 释放内存 delVector(path); delVector(res); return 0; }