Merge pull request TheAlgorithms#426 from pomkarnath98/rotate-list-right

pomkarnath98 · web-flow · commit c6b95c29e25b · 2020-10-10T13:02:44.000+05:30
Added Rotate List Right by k places to the list
diff --git a/Data-Structures/Linked-List/RotateListRight.js b/Data-Structures/Linked-List/RotateListRight.js
@@ -0,0 +1,45 @@
+/**
+ * A LinkedList based solution for Rotating a List to the right by k places
+ */
+
+function main () {
+  /*
+  Problem Statement:
+  Given a linked list, rotate the list to the right by k places, where k is non-negative.
+
+  Note:
+  * While Solving the problem in given link below, don't use main() function.
+  * Just use only the code inside main() function.
+  * The purpose of using main() function here is to aviod global variables.
+
+  Link for the Problem: https://leetcode.com/problems/rotate-list/
+  */
+  // Reference to both head and k is given in the problem. So please ignore below two lines
+  let head = ''
+  let k = ''
+  let i = 0
+  let current = head
+  while (current) {
+    i++
+    current = current.next
+  }
+  k %= i
+  current = head
+  let prev = null
+  while (k--) {
+    if (!current || !current.next) {
+      return current
+    } else {
+      while (current.next) {
+        prev = current
+        current = current.next
+      }
+      prev.next = current.next
+      current.next = head
+      head = current
+    }
+  }
+  return head
+}
+
+main()
