CODEWITHSUNDEEP
javadata-structureslinked-list
Krunal
Krunal

Reputation: 11

Swap two Nodes of LinkedList

**You have been given a singly linked list of integers along with two integers, 'i,' and 'j.' Swap the nodes that are present at the 'i-th' and 'j-th' positions.

My code is as below, can you suggest an efficient alternate way?**

public static LinkedListNode<Integer> swapNodes(LinkedListNode<Integer> head, int i, int j) {
        //Your code goes here
        LinkedListNode<Integer> temp=head;
        LinkedListNode<Integer> temp1=head;
        LinkedListNode<Integer> tempo=new LinkedListNode<Integer>(0);
        int beg=0, end=0;
   
       for(int x=0;x<i;x++)
        {      
            temp=temp.next;
           
        }

        for(int y=0;y<j;y++)
        {
            temp1=temp1.next;
        
        }
   
       tempo.data= temp.data;
        temp.data= temp1.data;
        temp1.data=tempo.data;
        
        
        return head;
        
    }

}

Upvotes: 0

Views: 451

Answers (1)

Wahidullah Shadab
Wahidullah Shadab

Reputation: 790

To make it more efficient you can remove one of the for loops. first add another variable named LinkedListNode<Integer> t=head;, then you can first check between i and j and see which one is bigger and do a for loop for that.

LinkedListNode<Integer> t=head;

int counter = (i > j) ? i : j;
for(int x=0;x<counter;x++)
{      
    t = t.next;
    if(counter == i-1){   
       temp=t.next;
    } 
    if(counter == j-1){
       temp1=t.next;
    }       
}

Upvotes: 1

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