class Solution:
    def binaryTreePaths(self, root):
        def dfs(node, path_list):
            if not node:
                return
            
            # 1. Add current value to the list
            path_list.append(str(node.val))
            
            # 2. Check for leaf
            if not node.left and not node.right:
                res.append("->".join(path_list))
            else:
                # 3. Recurse down
                dfs(node.left, path_list)
                dfs(node.right, path_list)
            
            # 4. BACKTRACK: Remove the node so it doesn't leak into the next path
            path_list.pop()

        res = []
        dfs(root, [])
        return res