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| class Solution {
private final List<List<Integer>> ans = new LinkedList<>();
public List<List<Integer>> pathSum(TreeNode root, int sum) {
dfs(root, new LinkedList<>(), sum);
return ans;
}
private void dfs(TreeNode root, List<Integer> path, int sum) {
if (root == null) {
return;
}
List<Integer> branch = new LinkedList<>(path);
branch.add(root.val);
if (isLeaf(root) && branch.stream().reduce(0, Integer::sum) == sum) {
ans.add(branch);
return;
}
dfs(root.left, branch, sum);
dfs(root.right, branch, sum);
}
private boolean isLeaf(TreeNode node) {
return node.left == null && node.right == null;
}
}
|
