Golang Program to insert a node at the ith index node, when the index is at the 0th position in the linked list.

Examples

Approach to solve this problem

Step 1 − Define a method that accepts the head of a linked list.

Step 2 − If head == nil, create a new node and make it head and return it as the new head.

Step 3 − When index == 0, then update the head.

Step 4 − Iterate the given linked list from its head. Also, initialize preNode that will keep the store address of the previous node.

Step 5 − If index i matches with the given index, then then delete that node.next, break the loop.

Step 6 − Return, at the end of loop.

Example

 Live Demo

package main import "fmt" type Node struct {    value int    next *Node } func NewNode(value int, next *Node) *Node{    var n Node    n.value = value    n.next = next    return &n } func TraverseLinkedList(head *Node){    temp := head    for temp != nil {       fmt.Printf("%d ", temp.value)       temp = temp.next    }    fmt.Println() } func InsertNodeAtIthIndex(head *Node, index, data int) *Node{    if head == nil{       head = NewNode(data, nil)       return head    }    if index == 0{       newNode := NewNode(data, nil)       newNode.next = head       head = newNode       return head    }    i := 0    temp := head    preNode := temp    for temp != nil {       if i == index{          newNode := NewNode(data, nil)          preNode.next = newNode          newNode.next = temp          break       }       i++       preNode = temp       temp = temp.next    }    return head } func main(){    head := NewNode(30, NewNode(10, NewNode(40, NewNode(40, nil))))    fmt.Printf("Input Linked list is: ")    TraverseLinkedList(head)    index := 0    head = InsertNodeAtIthIndex(head, index, 5)    fmt.Printf("Inserting new node at %dth index, Linked List is: ", index)    TraverseLinkedList(head) }

Output

Input Linked list is: 30 10 40 40 Inserting new node at 0th index, Linked List is: 5 30 10 40 40