Inserting a Node in Sorted List

Procedure to insert a new node in a sorted linked list.

Procedure :

  • Create a new node and assign the data to it.
  • Check if the head node is NULL. If it is, no nodes are present in the linked list and the new node will be the head.
  • Check if the head node's data is greater than the data to be inserted. If so, the new node will become the head node.
  • If nodes are already present, reach the proper position by checking if the data of next node in each iteration is less than the data to be inserted.
  • Once the position is reached, set the next of new node to be the next of current node.
  • Finally, set next of current node to new node.
void insert(struct node *ptr, int data) {
​
// Creating a node
struct node *newNode;
newNode = (struct node *)malloc(sizeof(struct node));
newNode -> data = data;
​
// If there are no nodes or first node data is greater
if (head == NULL || head -> data > data) {
newNode -> next = head;
head = newNode;
}
// Inserting at correct position
else {
while (ptr -> next != NULL && ptr -> next -> data < data) {
ptr = ptr -> next;
}
newNode -> next = ptr -> next;
ptr -> next = newNode;
}
​
}
Contributed by Nitin Ranganath