题解 | #按之字形顺序打印二叉树#
按之字形顺序打印二叉树
https://www.nowcoder.com/practice/91b69814117f4e8097390d107d2efbe0
/** * struct TreeNode { * int val; * struct TreeNode *left; * struct TreeNode *right; * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {} * }; */ #include <algorithm> #include <deque> #include <queue> #include <vector> class Solution { public: /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param pRoot TreeNode类 * @return int整型vector<vector<>> */ vector<vector<int> > Print(TreeNode* pRoot) { // write code here if (pRoot == nullptr) { return m_retVal; } bool flag = true; queue<TreeNode*> qu; qu.push(pRoot); while (!qu.empty()) { vector<int> tempVec; int size = qu.size(); for (int i = 0; i < size; ++i) { TreeNode* tempNode = qu.front(); tempVec.push_back(tempNode->val); qu.pop(); if (tempNode->left) { qu.push(tempNode->left); } if (tempNode->right) { qu.push(tempNode->right); } } if (!flag) { reverse(tempVec.begin(), tempVec.end()); } flag = !flag; m_retVal.push_back(tempVec); } return m_retVal; } private: std::vector<vector<int>> m_retVal; };