Create 25. Reverse Nodes in k-Group

Author: rajatag03

25. Reverse Nodes in k-Group

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+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode() {}
+ *     ListNode(int val) { this.val = val; }
+ *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+ * }
+ */
+class Solution {
+    public ListNode reverseKGroup(ListNode head, int k) {
+        int count =0;
+        ListNode dummy = new ListNode();
+        dummy.next = head;
+        
+        ListNode temp = dummy;
+        
+        while(temp.next!=null){
+            temp = temp.next;
+            count++;
+        }
+        temp = dummy;
+        while(temp.next!=null){
+            if(count<k) break;
+            int nodes = k-1;
+            ListNode tempnext = temp.next;
+            ListNode first = temp.next;
+            ListNode second = first.next;
+            
+            while(nodes-- > 0){
+                ListNode next = second.next;
+                second.next = first;
+                first = second;
+                second = next;
+            }
+            count-=k;
+            temp.next = first;
+            tempnext.next = second;
+            temp = tempnext;
+            
+        }
+        return dummy.next;
+    }
+}