103:Binary Tree Zigzag Level Order Traversal【树】【BFS】【栈】

题目链接：click~

/*题意：对一颗二叉树进行Z字行一层一层的遍历*/class Solution {public:    void DFS(TreeNode *T, int level, vector<vector<int>> &path) {        if(T == NULL) return;        if(level == path.size()) {            path.resize(level+1);        }        path[level].push_back(T->val);        DFS(T->left, level+1, path);        DFS(T->right, level+1, path);    }    vector<vector<int> > zigzagLevelOrder(TreeNode *root) {        vector<vector<int>> path;        if(root == NULL) return path;        DFS(root, 0, path);        int len = path.size();        for(int i = 1; i < len; i += 2)            reverse(path[i].begin(), path[i].end());    }};