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]
]
public List<List<Integer>> pathSum(TreeNode root, int sum) {
List<List<Integer>> result = new ArrayList<>();
pathSum(result, new ArrayList<Integer>(), root, sum);
return result;
}
public void pathSum(List<List<Integer>> result, ArrayList<Integer> temp, TreeNode root, int target) {
if(root == null) return;
if(root.val == target && root.left == null && root.right == null) {
temp.add(root.val);
result.add(new ArrayList<>(temp));
temp.remove(temp.size()-1);
return;
}
temp.add(root.val);
pathSum(result, temp, root.left, target-root.val);
pathSum(result, temp, root.right, target-root.val);
temp.remove(temp.size()-1);
}