Advent of Code 2017 Day 7

Day7.java

package Advent2017;

import util.FileIO;

import java.util.*;

public class Day7 {

    private static int sumOfChildren(List<Leaf> children) {
        if (children.size() == 0) return 0;
        int sum = 0;
        int target = 0;
        for (Leaf each : children){
            if (each.children.size() == 0) {
                sum += each.weight;
                if (target == 0) target = each.weight;
            } else {

                int subtotal = sumOfChildren(each.children);
                each.weightOfChildren = subtotal;
                subtotal += each.weight;
                if (target == 0) target = subtotal;
                sum += subtotal;
            }
        }
        if (sum / children.size() != target) {
            System.out.println("unbalanced : " + children);
            System.out.println("Sum :" + sum + " Target :" + target);
            System.out.println("actual:" + (sum/children.size()));
        }
        return sum;
    }

    static class Leaf {
        String name;
        int weight;
        int weightOfChildren;
        Leaf parent;
        List<Leaf> children;
        Leaf(String name, int weight){
            this.name = name;
            this.weight = weight;
            children = new ArrayList<>();
        }

        @Override
        public String toString() {
            return "Leaf{" +
                    "name='" + name + '\'' +
                    ", weight=" + weight +
                    ", children =" + children.size() +
                    ", wt of ch:" + weightOfChildren +
                    ", sum :" + (weight + weightOfChildren) +
                    '}';
        }
    }

    public static void main(String[] args) {
        List<String> input = FileIO.getAOCInputForDay(2017, 7, FileIO.SESSION_ID);
        Leaf root = null;
        System.out.println(input.size());
        Map<String, Leaf> tree = new HashMap<>();
        for (String each : input) {
            String[] split = each.split(" ");
            int weight = Integer.parseInt(split[1].replaceAll("[()]", ""));
            Leaf node = new Leaf(split[0], weight);
            tree.put(split[0], node);
        }

        for (String each : input) {
            String[] split = each.split(" ");
            Leaf parent = tree.get(split[0]);
            if (split.length > 2) {
                for (int i = 3; i < split.length; i++) {
                    String name = split[i].replaceAll(",", "");
                    Leaf child = tree.get(name);
                    child.parent = parent;
                    parent.children.add(child);
                }
            }
        }
        for (Map.Entry each : tree.entrySet()) {
            Leaf troot = (Leaf) each.getValue();
            if (troot.parent == null) {
                System.out.println(troot.name);
                root = troot;
            }

        }
        System.out.println(sumOfChildren(root.children));
    }
}