Leetcode Populating Next Right Pointers in Each Node II problem solution

class Solution:
    def connect(self, root: 'Node') -> 'Node':
        ans=[]
        def dfs(node,level):
            if not(node):
                return
            if level==len(ans):
                ans.append([])
            if not(ans[level]):
                ans[level].append(node)
            else:
                ans[level][-1].next=node
                ans[level].append(node)
            dfs(node.left,level+1)
            dfs(node.right,level+1)
        dfs(root,0)
        return root

public class Solution {   
    public void connect(TreeLinkNode root) {
        connect(root, null);
    }
    
    private void connect(TreeLinkNode root, TreeLinkNode right) {
        if (root == null) return;
        root.next = right;
        TreeLinkNode nextRight = getNextRight(right);
        connect(root.right, nextRight);
        connect(root.left, root.right != null? root.right : nextRight);
    }
    
    private TreeLinkNode getNextRight(TreeLinkNode root) {
        if (root == null) return null;
        TreeLinkNode nextRight = root.left != null? root.left : root.right;
        return nextRight != null? nextRight : getNextRight(root.next);
    }
}

class Solution {
public:
    Node* connect(Node* root) {
        if (!root) return root;
        queue<Node*>q;
        q.push(root);
        while (q.size()){
            int sz = q.size();
            for (int i = 0; i < sz; i ++){
                auto p = q.front(); q.pop();
                if (i != sz - 1) p->next = q.front();
                else p->next = NULL;
                if (p->left) q.push(p->left);
                if (p->right) q.push(p->right);
            }
        }
        return root;
    }
};

void dfs_fun(struct TreeLinkNode* node,struct TreeLinkNode* next) {
	if(NULL==node) return;
	node->next=next;
	struct TreeLinkNode *beyond_r=NULL;
	while(NULL!=next){
		if(NULL!=next->left){
			beyond_r=next->left;
			break;
		}

		if(NULL!=next->right){
			beyond_r=next->right;
			break;
		}

		next=next->next;
	}

	dfs_fun(node->right,beyond_r);
	dfs_fun(node->left,node->right?node->right:beyond_r);
}

void connect(struct TreeLinkNode *root) {
	dfs_fun(root,NULL);
}