113. 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.
Note: A leaf is a node with no children.
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] ]
-
private List<IList<int>> list = new List<IList<int>>(); public IList<IList<int>> PathSum(TreeNode root, int sum) { Chuck(root, sum, 0, string.Empty); return list; } private void Chuck(TreeNode node, int sum, int tempSum, string str) { if (node == null) { return; } tempSum = tempSum + node.val; var left = node.left; var right = node.right; if (string.IsNullOrEmpty(str)) { str = $"{node.val}"; } else { str = $"{str},{node.val}"; } if (left == null && right == null) { if (tempSum == sum) { var tempList = str.Split(',').Select(x => Convert.ToInt32(x)).ToList(); list.Add(tempList); } } else { Chuck(left, sum, tempSum, str); Chuck(right, sum, tempSum, str); } }
Runtime: 288 ms, faster than 21.95% of C# online submissions for Path Sum II.
Memory Usage: 34.2 MB, less than 13.98% of C# online submissions forPath Sum II.