Merge pull request #955 from min8grace/main

davemin/2024-06-24-1721-Swapping-Nodes-in-a-Linked-List.cs

@@ -0,0 +1,35 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
+public class Solution {
+    public ListNode SwapNodes(ListNode head, int k) {
+        ListNode firstNode = head;
+        ListNode secondNode = head;
+
+        while(k-1>0){
+            firstNode = firstNode.next;
+            k--;   
+        }
+
+        // while keeping k-gap, move two node parallelly till the first node ends.        
+        ListNode kStepAhead = firstNode;
+        while(kStepAhead.next!= null){
+            kStepAhead = kStepAhead.next;
+            secondNode = secondNode.next;
+        }
+        // swap two nodes.
+        int temp = firstNode.val;
+        firstNode.val = secondNode.val;
+        secondNode.val = temp;
+
+        return head;
+    }
+}

davemin/2024-06-24-61-Rotate-List.cs

@@ -0,0 +1,35 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
+public class Solution {
+    public ListNode RotateRight(ListNode head, int k) {
+        if (head == null)
+        {
+            return null;
+        }
+        ListNode tail = head;
+        int length = 1;
+        while(tail.next != null){
+            Console.WriteLine(tail.val);
+            tail = tail.next;
+            length++;
+        }
+        tail.next = head;
+         k = length - k % length;
+        while(k>0){
+            head = head.next;
+            tail = tail.next;            
+            k--;
+        }
+        tail.next = null;
+        return head;
+    }
+}