# Linked List | Set 3 (Deleting a node)

We have discussed Linked List Introduction and Linked List Insertion in previous posts on singly linked list.
Let us formulate the problem statement to understand the deletion process. Given a ‘key’, delete the first occurrence of this key in linked list.
To delete a node from linked list, we need to do following steps.
1) Find previous node of the node to be deleted.
2) Changed next of previous node.
3) Free memory for the node to be deleted.
Since every node of linked list is dynamically allocated using malloc() in C, we need to call free() for freeing memory allocated for the node to be deleted.
 `// A complete working C program to demonstrate deletion in singly` `// linked list` `#include ` `#include `   `// A linked list node` `struct` `node` `{` `    ``int` `data;` `    ``struct` `node *next;` `};`   `/* Given a reference (pointer to pointer) to the head of a list` `   ``and an int, inserts a new node on the front of the list. */` `void` `push(``struct` `node** head_ref, ``int` `new_data)` `{` `    ``struct` `node* new_node = (``struct` `node*) ``malloc``(``sizeof``(``struct` `node));` `    ``new_node->data  = new_data;` `    ``new_node->next = (*head_ref);` `    ``(*head_ref)    = new_node;` `}`   `/* Given a reference (pointer to pointer) to the head of a list` `   ``and a key, deletes the first occurrence of key in linked list */` `void` `deleteNode(``struct` `node **head_ref, ``int` `key)` `{` `    ``// Store head node` `    ``struct` `node* temp = *head_ref, *prev;`   `    ``// If head node itself holds the key to be deleted` `    ``if` `(temp != NULL && temp->data == key)` `    ``{` `        ``*head_ref = temp->next;   ``// Changed head` `        ``free``(temp);               ``// free old head` `        ``return``;` `    ``}`   `    ``// Search for the key to be deleted, keep track of the` `    ``// previous node as we need to change 'prev->next'` `    ``while` `(temp != NULL && temp->data != key)` `    ``{` `        ``prev = temp;` `        ``temp = temp->next;` `    ``}`   `    ``// If key was not present in linked list` `    ``if` `(temp == NULL) ``return``;`   `    ``// Unlink the node from linked list` `    ``prev->next = temp->next;`   `    ``free``(temp);  ``// Free memory` `}`   `// This function prints contents of linked list starting from ` `// the given node` `void` `printList(``struct` `node *node)` `{` `    ``while` `(node != NULL)` `    ``{` `        ``printf``(``" %d "``, node->data);` `        ``node = node->next;` `    ``}` `}`   `/* Drier program to test above functions*/` `int` `main()` `{` `    ``/* Start with the empty list */` `    ``struct` `node* head = NULL;`   `    ``push(&head, 7);` `    ``push(&head, 1);` `    ``push(&head, 3);` `    ``push(&head, 2);`   `    ``puts``(``"Created Linked List: "``);` `    ``printList(head);` `    ``deleteNode(&head, 1);` `    ``puts``(``"\nLinked List after Deletion of 1: "``);` `    ``printList(head);` `    ``return` `0;` `}`

Output:
```Created Linked List:
2  3  1  7
Linked List after Deletion of 1:
2  3  7```