提交103 二叉树锯齿形遍历

yllg · yllg · commit 7ca04efeac2b · 2019-03-27T21:41:22.000+08:00
diff --git a/103.二叉树锯齿层次遍历/103 solution.html b/103.二叉树锯齿层次遍历/103 solution.html
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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta http-equiv="X-UA-Compatible" content="ie=edge">
+    <title>Document</title>
+</head>
+<body>
+<script>
+// Source : https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/
+// Author : 悬笔e绝
+// Date   : 2019-03-27
+
+// Definition for a binary tree node.
+function TreeNode(val) {
+    this.val = val;
+    this.left = this.right = null;
+}
+
+/**
+ * @param {TreeNode} root
+ * @return {number[][]}
+ */
+ var zigzagLevelOrder = function(root) {
+  var maxn = -1;
+  var ans = [];
+  dfs(root, 0);
+
+  function dfs(node, step) {
+    if (!node)
+      return;
+    maxn = step > maxn ? step : maxn;
+    if (!ans[step])
+      ans[step] = [];
+    ans[step].push(node.val);
+    dfs(node.left, step + 1);
+    dfs(node.right, step + 1);
+  }
+
+  for (var i = 0; i <= maxn; i++)
+    (i & 1) && (ans[i].reverse());
+  return ans;
+};
+
+// 测试
+var tree_node_1_1 = new TreeNode(9);
+var tree_node_1_2 = new TreeNode(20);
+tree_node_1_2.left = new TreeNode(15);
+tree_node_1_2.right = new TreeNode(7);
+var tree_node_1 = new TreeNode(3);
+tree_node_1.left = tree_node_1_1;
+tree_node_1.right = tree_node_1_2;
+console.log(zigzagLevelOrder(tree_node_1));
+
+// [
+//   [3],
+//   [20,9],
+//   [15,7]
+// ]
+
+</script>
+</body>
+</html>
