Update Leetcode-116. Populating Next Right Pointers in Each Node.cpp

Trees/Leetcode-116. Populating Next Right Pointers in Each Node.cpp

@@ -1,21 +1,31 @@
 class Solution {
 public:
-
  Node* connect(Node* root) {
- if(root==NULL)
- return NULL;
-
- if(root->left){
- root->left->next=root->right;
-
- if(root->next){
- root->right->next=root->next->left;
- }
-
- connect(root->left);
- connect(root->right);
+ if (!root) return NULL;
+
+ Node* leftmost = root; // Start at the root level
+
+ while (leftmost) {
+ Node* dummy = new Node(0); // Dummy node for next level
+ Node* temp = dummy; // Pointer to build next level links
+
+ Node* curr = leftmost;
+ while (curr) {
+ if (curr->left) {
+ temp->next = curr->left;
+ temp = temp->next;
+ }
+ if (curr->right) {
+ temp->next = curr->right;
+ temp = temp->next;
+ }
+ curr = curr->next; // Move to next node in current level
+ }
+
+ leftmost = dummy->next; // Move to next level
+ delete dummy; // Free dummy node
  }
+
  return root;
-
  }
-};
+};