Ch5 DFS - Bootstrap your algorithms.java

package com.NineChapters.TreeBasedDFS.SumPath;

import com.TreesUtil.TreeNode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Minimum_subtree_596 {
    private final static Logger logger = LoggerFactory.getLogger(Minimum_subtree_596.class);

    public static void main(String[] args) {
        testMinimum_subtree_596();
    }

    private static void testMinimum_subtree_596() {
        TreeNode root = new TreeNode(1);
        root.left = new TreeNode(-5);
        root.left.left = new TreeNode(0);
        root.left.right = new TreeNode(2);
        root.right = new TreeNode(2);
        root.right.left = new TreeNode(-4);
        root.right.right = new TreeNode(-5);
        logger.info("result 1 v.s. {}", findSubtree(root));
    }

    private static TreeNode subtree = null;
    private static int subtreeSum = Integer.MAX_VALUE;

    public static TreeNode findSubtree(TreeNode root) {
        // filter abnormal cases
        if (root == null) {
            return root;
        }

        subtree = null;
        subtreeSum = Integer.MAX_VALUE;
        helper(root);

        // return the final result
        return subtree;
    }

    private static int helper(TreeNode node) {
        if (node == null) {
            return Integer.MAX_VALUE;
        }

        int sum = node.val;
        if (node.left != null) {
            sum += helper(node.left);
        }
        if (node.right != null) {
            sum += helper(node.right);
        }
        if (sum < subtreeSum) {
            subtreeSum = sum;
            subtree = node;
        }
        return sum;
    }

    private static class MyLogger {
        private static final boolean isDebugging = false;
        private static final boolean isInfoing = true;
        private static final String DEBUG = "[DEBUG]";
        private static final String INFO = "[INFO]";

        static void debug(Object message) {
            if (isDebugging) {
                System.out.println(DEBUG + " = " + message);
            }
        }

        static void info(Object message) {
            if (isInfoing) {
                System.out.println(INFO + " = " + message);
            }
        }
    }
}