> For the complete documentation index, see [llms.txt](https://mayanktyagi3111.gitbook.io/interview-prep/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mayanktyagi3111.gitbook.io/interview-prep/trees/path-sum-ii.md).

# 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]
]
```

```java
class Solution {
    public void backtrack(TreeNode root, int sum, List<List<Integer>> ans, ArrayList<Integer> temp, int currentSum) {
        if (root == null)
            return;
        if (root.left == null && root.right == null) {
            if (currentSum + root.val == sum) {
                temp.add(root.val);
                ans.add(new ArrayList<>(temp));
                temp.remove(temp.size() - 1);
            }
            return;
        }
        temp.add(root.val);
        backtrack(root.left, sum, ans, temp, currentSum + root.val);
        backtrack(root.right, sum, ans, temp, currentSum + root.val);
        temp.remove(temp.size() - 1);
    }

    public List<List<Integer>> pathSum(TreeNode root, int sum) {
        List<List<Integer>> ans = new ArrayList<>();
        backtrack(root, sum, ans, new ArrayList<Integer>(), 0);
        return ans;
    }
}
```