打印书树中结点值为目标值的路径_24

public ArrayList<ArrayList<Integer>> FindPath(TreeNode root, int target) {
        ArrayList<ArrayList<Integer>> pathList = new ArrayList<>();
        ArrayList<Integer> currList = new ArrayList<>();
        if (root==null){
            return pathList;
        }

        getAllPath(root, target, 0, currList, pathList);
        return pathList;
    }

    private void getAllPath(TreeNode root, int target, int currentSum, ArrayList<Integer> currList, ArrayList<ArrayList<Integer>> pathList) {
        if (root.left == null && root.right == null) {
            if (target == root.val + currentSum) {
                currList.add(root.val);
                pathList.add(currList);
            }
            return;
        }
        if (root.left != null) {
            currentSum += root.val;
            currList.add(root.val);
            getAllPath(root.left, target, currentSum, new ArrayList<>(currList), pathList);
            currentSum-=root.val;
            currList.remove(currList.size()-1);
        }
        if (root.right != null) {
            currentSum += root.val;
            currList.add(root.val);
            getAllPath(root.right, target, currentSum, new ArrayList<>(currList), pathList);
        }