Find the max avg score in a N-ary Tree

Question

I want to display the maximum average score of an n-ary Tree where average = sum of values of childnodes / number of child nodes. My node is defined like this

class NaryNode {
int value;
NaryNode parent;
List<NaryNode> children = new ArrayList<NaryNode>();

NaryNode(int x) {
    this.value = x;
}

public void addChild(NaryNode childNode) {
    childNode.parent = this;
    this.children.add(childNode);
  }

}


public class NaryTree {
public NaryNode root = new NaryNode(10);

public NaryTree() {
    root.parent = null;
}

public void traverseTree(NaryNode rootNode)// depth first
{
    System.out.println(rootNode.value);
    if (rootNode.children.size() != 0)
        for (NaryNode ch : rootNode.children)
            traverseTree(ch);
}

public static void main(String[] args) {
    NaryTree mytree = new NaryTree();

    NaryNode n2 = new NaryNode(20);
    NaryNode n3 = new NaryNode(3);
    NaryNode n4 = new NaryNode(15);

    NaryNode n5 = new NaryNode(8);
    NaryNode n6 = new NaryNode(45);
    NaryNode n7 = new NaryNode(22);

    NaryNode n8 = new NaryNode(11);
    NaryNode n9 = new NaryNode(16);
    NaryNode n10 = new NaryNode(18);

    NaryNode n11 = new NaryNode(7);

    mytree.root.addChild(n2);
    mytree.root.addChild(n3);
    mytree.root.addChild(n4);

    n2.addChild(n5);
    n2.addChild(n6);
    n2.addChild(n7);

    n3.addChild(n8);
    n3.addChild(n9);
    n3.addChild(n10);

    n4.addChild(n11);

    // mytree.traverseTree(mytree.root);
    int max = Integer.MIN_VALUE;
    int maxavg = calculateaverage(mytree.root,max);
    System.out.println(maxavg);
}

private static int calculateaverage(NaryNode root,int max) {
    int sum = 0;
    int count =0;
    if(root.children.size() == 0)
        return root.value;
    for(NaryNode cc : root.children){
        sum += calculateaverage(cc,max);
        count++;
    }
    sum = sum/count;
    if(sum>max)
        max = sum;
    return max;
}

 }

I have written the below logic but it is giving me wrong answer as my logic is incorrect. Can you point out where i am going wrong??

Answer 1

You have to update your max value for every child that has children. Try this:

private static int calculateaverage(NaryNode root,int max) {
    int sum = 0;
    int count =0;
    if(root.children.size() == 0)
        return root.value;
    for(NaryNode cc : root.children){
        if(cc.children.size() > 0){
            int tmp = calculateaverage(cc,max);
            if(tmp>max){
                max = tmp;
            }
        }
        sum+=cc.value;
        count++;
    }
    sum = sum/count;
    if(sum>max)
        max = sum;
    return max;
}

Note: You might want to use doubles for average.