Sum of elements in "manual" Linked list java

Question

I have a question about how to write a function that will give me the sum of elements in a manual linked list. I tried it like this but it doesn't work: function insert() inserts elements in list.

public class list {
            int head;
            List tail;
            int sum=0;
            int value;
    public void insert(int elt){
        if(tail == null){

            tail = new list();
            tail.head = elt;

        }
        else{
        tail.insert(elt);
        }
    }
    public int sum(list head){
            if(head!=null){
                sum += head;
                return tail.sum(head);
            }
            return sum;
        }
}

Better to use English named variables, and `Seznam` is not a known type. — user1803551, Dec 02 '17 at 15:14
Doesn't tell us anything, we don't know what it is. See [MCVE] and [ask]. — user1803551, Dec 02 '17 at 15:16
Possible duplicate of [How to get the sum of a LinkedList](https://stackoverflow.com/questions/24102194/how-to-get-the-sum-of-an-linkedlist-sum-up-items-in-a-linkedlist). — user1803551, Dec 02 '17 at 15:18
it is not duplicate because i am not getting elements from database. — Comp, Dec 02 '17 at 15:19
Please [edit] your question to show all of the code that we would need to understand your code. You haven't given enough information. — 4castle, Dec 02 '17 at 15:41

daniu · Accepted Answer · 2017-12-02T15:44:40.973

2

Code for this kind of things (ie "manual" linked list iteration) is like this :

public int calculateSum(MyList list) {
    Node node = list.head();
    int sum = 0;
    while (node != null) {
        sum += node.value();
        node = node.next();
    }
    return sum;
}

With

class MyList {
    public Node head();
} 

class Node {
    public int value() ;
    public Node next() ;
}

edited Dec 02 '17 at 15:44

answered Dec 02 '17 at 15:34

daniu

14,137
4
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Could you please write the whole function so i see which arguments are needed in the function – Comp Dec 02 '17 at 15:38
You will need to write the `MyList` and `Node` classes yourself though. – daniu Dec 02 '17 at 15:47

score 1 · Answer 2 · answered Dec 02 '17 at 15:20

1

Why don't you use List Object from java ? You can use this function for sum of elements in a list :

public static int sum (List<Integer> list) {
    int sum = 0;
    for (int i: list) {
        sum += i;
    }
    return sum;
}

answered Dec 02 '17 at 15:20

Ahmadreza

939
1
9
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Sum of elements in "manual" Linked list java

2 Answers2