Create insert-into-a-cyclic-sorted-list.cpp

Author: kamyu104

C++/insert-into-a-cyclic-sorted-list.cpp

@@ -0,0 +1,56 @@
+// Time:  O(n)
+// Space: O(1)
+
+/*
+// Definition for a Node.
+class Node {
+public:
+    int val;
+    Node* next;
+
+    Node() {}
+
+    Node(int _val, Node* _next) {
+        val = _val;
+        next = _next;
+    }
+};
+*/
+class Solution {
+public:
+    Node* insert(Node* head, int insertVal) {
+        if (head == nullptr) {
+            auto node = new Node(insertVal, nullptr);
+            node->next = node;
+            return node;
+        }
+        auto curr = head;
+        while (true) {
+            if (curr->val < curr->next->val) {
+                if (curr->val <= insertVal &&
+                    insertVal <= curr->next->val) {
+                    insertAfter(curr, insertVal);
+                    break;
+                }
+            } else if (curr->val > curr->next->val) {
+                if (curr->val <= insertVal ||
+                    insertVal <= curr->next->val) {
+                    insertAfter(curr, insertVal);
+                    break;
+                }
+            } else {
+                if (curr->next == head) {
+                    insertAfter(curr, insertVal);
+                    break;
+                }
+            }
+            curr = curr->next;
+        }
+        return head; 
+    }
+
+private:
+    void insertAfter(Node *node, int val) {
+        node->next = new Node(val, node->next);
+    }
+};