3

Author: kedebug

PopulatingNextRightPointersinEachNodeII/PopulatingNextRightPointersinEachNodeII.cpp

@@ -0,0 +1,56 @@
+/**
+ * Definition for binary tree with next pointer.
+ * struct TreeLinkNode {
+ *  int val;
+ *  TreeLinkNode *left, *right, *next;
+ *  TreeLinkNode(int x) : val(x), left(NULL), right(NULL), next(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    void connect(TreeLinkNode *root) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        
+        TreeLinkNode *link_head = root;
+        
+        while (link_head) {
+            TreeLinkNode *next_link_head = NULL;
+            TreeLinkNode *next_link_node = NULL;
+            
+            while (link_head) {
+                if (link_head->left) {
+                    next_link_head = link_head->left;
+                    next_link_node = next_link_head;
+                }
+                if (link_head->right) {
+                    if (next_link_node) {
+                        next_link_node->next = link_head->right;
+                        next_link_node = next_link_node->next;
+                    }
+                    else {
+                        next_link_head = link_head->right;
+                        next_link_node = next_link_head;
+                    }
+                }
+                if (next_link_head) break;
+                link_head = link_head->next;
+            }
+            if (next_link_head == NULL) break;
+            
+            while (link_head->next) {
+                if (link_head->next->left) {
+                    next_link_node->next = link_head->next->left;
+                    next_link_node = next_link_node->next;
+                }
+                if (link_head->next->right) {
+                    next_link_node->next = link_head->next->right;
+                    next_link_node = next_link_node->next;
+                }
+                link_head = link_head->next;
+            }
+            link_head = next_link_head;
+        }
+    }
+};
+