Rotate_linkedList.cpp

#include <bits/stdc++.h>
using namespace std;

struct Node {
    int data;
    struct Node *next;
    Node(int x) {
        data = x;
        next = NULL;
    }
};



class Solution
{
    public:
    
    Node* rotate(Node* head, int k)
    {
        if(head==NULL||head->next==NULL||k==0)
        {
            return head;
        }
        Node* temp=head;
        while(temp->next!=NULL)
        {
            temp=temp->next;
        }
        temp->next=head;
        Node* newHead;
        temp=head;
        int i=1;
        while(i<k){
            temp=temp->next;
            i++;
        }
        newHead=temp->next;
        temp->next=NULL;
        return newHead;
        
    }
};
    


void printList(Node *n)
{
    while (n != NULL)
    {
        cout<< n->data << " ";
        n = n->next;
    }
    cout<< endl;
}

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int n, val, k;
        cin>>n;
        
        cin>> val;
        Node *head = new Node(val);
        Node *tail = head;
        
        for(int i=0; i<n-1; i++)
        {
            cin>> val;
            tail->next = new Node(val);
            tail = tail->next;
        }
        
        cin>> k;
        
        Solution ob;
        head = ob.rotate(head,k);
        printList(head);
    }
    return 1;
}

//time complexity O(n)
//space complexity O(1)