print all root to leaf paths in a binary tree

Question

i am trying to print all root to leaf paths in a binary tree using java.

public void printAllRootToLeafPaths(Node node,ArrayList path) 
{
    if(node==null)         


        

Answer 1

This is my solution for storing all path values in List and then just print the list

Basically what code is recursively calling rootToLeafPaths method and passing the string on values separated by comma (","). The base condition for recursive function is when we reach leaf node (both children are null). At that time, we are just extracting int values from string and storing it in List

class Solution {
    public void printBTfromRootToLeaf (TreeNode root) {
        if(root == null) return 0;
        if (root.left == null & root.right == null) return 1;
        List> res = new ArrayList();
        rootToLeafPaths(root, res, "");
        System.out.println(res);
    }
private void rootToLeafPaths(TreeNode root, List> res, String curr) {
        if (root.left == null && root.right == null) {
            String[] vals = curr.split(",");
            List temp = new ArrayList<>();
            for (String val : vals) temp.add(Integer.parseInt(val));
            temp.add(root.val);
            res.add(new ArrayList<>(temp));
        }
        if (root.left != null) rootToLeafPaths(root.left, res, curr + root.val + ",");
        if (root.right != null) rootToLeafPaths(root.right, res, curr + root.val + ",");
    }
}