# Sum of all Nodes

### Iterative Method :

```c
int sum(struct node *ptr) {

    // A variable to keep track of sum
    int sum = 0;
    
    // Iterate till ptr becomes NULL
    while (ptr != NULL) {
        sum += ptr -> data;
        ptr = ptr -> next;
    }
    return sum;
    
}
```

### Recursive Method :

```c
int sum(struct node *ptr) {

    // Base condition for termination
    if (p == NULL) {
        return 0;
    }
    
    // Recursive call
    else {
        return sum(ptr -> next) + p -> data;
    }

}
```

### Time and Space Complexity :

{% tabs %}
{% tab title="Iterative" %}
Time complexity : **O(n)**\
Space complexity : **O(n)**
{% endtab %}

{% tab title="Recursive" %}
Time complexity : **O(n)**\
Space complexity : **O(1)**
{% endtab %}
{% endtabs %}

Contributed by Nitin Ranganath


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://nitinranganath.gitbook.io/data-structures/linked-list/sum-of-all-nodes.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.