/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { List<String> res = new ArrayList<>(); public List<String> binaryTreePaths(TreeNode root) { if(root == null) return res; StringBuilder str = new StringBuilder(); dfs(root, str.append(root.val)); return res; } void dfs(TreeNode node, StringBuilder str){ if(node.left==null && node.right==null){ res.add(str.toString()); } //node is not null if(node.left != null){ str.append("->"); str.append(node.left.val); //Integer num = dfs(node.left, str); str.setLength(str.length() - 2 - (String.valueOf(node.left.val).length() )); } if(node.right != null){ str.append("->"); str.append(node.right.val); dfs(node.right, str); str.setLength(str.length() - 2 - (String.valueOf(node.right.val).length() )); } } }
Leetcode 257
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转载自www.cnblogs.com/stiles/p/leetcode257.html
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