[Leetcode] Path Sum II
Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.
For example:
Given the below binary tree and sum = 22
,
5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1
return
[ [5,4,11,2], [5,8,4,5] ]
1 /** 2 * Definition for binary tree 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 public class Solution { 11 public List<List<Integer>> pathSum(TreeNode root, int sum) { 12 List<List<Integer>> result=new ArrayList<List<Integer>>(); 13 List<Integer> tmp=new ArrayList<Integer>(); 14 dfs(result,tmp,sum,root,0); 15 return result; 16 } 17 18 private void dfs(List<List<Integer>> result, List<Integer> tmp, int sum, TreeNode root, int curSum) { 19 // TODO Auto-generated method stub 20 if(root==null) 21 return; 22 if(root.left==null&&root.right==null){ 23 if(curSum+root.val==sum){ 24 tmp.add(root.val); 25 result.add(new ArrayList<Integer>(tmp)); 26 tmp.remove(tmp.size()-1); 27 return; 28 } 29 return; 30 } 31 tmp.add(root.val); 32 dfs(result,tmp,sum,root.left,curSum+root.val); 33 dfs(result,tmp,sum,root.right,curSum+root.val); 34 tmp.remove(tmp.size()-1); 35 } 36 }