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Diffstat (limited to 'other/binary_tree_zigzag.cpp')
-rw-r--r-- | other/binary_tree_zigzag.cpp | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/other/binary_tree_zigzag.cpp b/other/binary_tree_zigzag.cpp new file mode 100644 index 0000000..186a99f --- /dev/null +++ b/other/binary_tree_zigzag.cpp @@ -0,0 +1,36 @@ +// 103. Binary Tree Zigzag Level Order Traversal +#include "leetcode.h" +// given the 'root' of 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) + +class Solution { +public: + vvd zigzagLevelOrder(TreeNode *root) { + if (!root) + return {}; + queue<TreeNode *> q; + vvd ans; + q.push(root); + int level = 0; + while (!q.empty()) { + int sz = q.size(); + vector<int> curr(sz); + for (int i = 0; i < sz; i++) { + TreeNode *tmp = q.front(); + q.pop(); + if (level == 0) + curr[i] = tmp->val; + else + curr[sz - i - 1] = tmp->val; + if (tmp->left) + q.push(tmp->left); + if (tmp->right) + q.push(tmp->right); + } + ans.push_back(curr); + level = !level; + } + return ans; + } +}; |