标签：注意 alter rsa while vector nat tree node bsp size
Given a binary tree, return the zigzag level order traversal of its nodes‘ values. (ie, from left to right, then right to left for the next level and alternate between).
For example:
Given binary tree [3,9,20,null,null,15,7],
3
/ 9 20
/ 15 7
return its zigzag level order traversal as:
[ [3], [20,9], [15,7] ]
分析： 层序遍历的，注意Zigzag的顺序
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: vector<vector<int>> zigzagLevelOrder(TreeNode* root) { vector<vector<int>> res; if(root == NULL) return res; queue<TreeNode* > nodesQue; bool flag = true; nodesQue.push(root); while(!nodesQue.empty()){ int size = nodesQue.size(); vector<int> temp(size,0); for(int i=0; i<size;i++){ TreeNode* node = nodesQue.front(); nodesQue.pop(); int index = flag? i: size-1-i; temp[index] = node->val; if(node->left) nodesQue.push(node->left); if(node->right) nodesQue.push(node->right); } flag = !flag; res.push_back(temp); } return res; } };
Binary Tree Zigzag Level Order Traversal
标签：注意 alter rsa while vector nat tree node bsp size
原文地址：http://www.cnblogs.com/willwu/p/6350191.html
