Simple QuadTree

Solution.java

import java.util.ArrayList;
import java.util.List;

/*
 *        N
 *      W    E
 *        S
 */

class Node {
    int x, y, value;

    Node(int x, int y, int value) {
        this.x = x;
        this.y = y;
        this.value = value; /* some data*/
    }
}
/* Using two points of Rectangular (Top,Left) & (Bottom , Right)*/
class Boundary {
    public int getxMin() {
        return xMin;
    }

    public int getyMin() {
        return yMin;
    }

    public int getxMax() {
        return xMax;
    }

    public int getyMax() {
        return yMax;
    }

    public Boundary(int xMin, int yMin, int xMax, int yMax) {
        super();
    /*
     *  Storing two diagonal points 
     */
        this.xMin = xMin;
        this.yMin = yMin;
        this.xMax = xMax;
        this.yMax = yMax;
    }

    public boolean inRange(int x, int y) {
        return (x >= this.getxMin() && x <= this.getxMax()
                && y >= this.getyMin() && y <= this.getyMax());
    }

    int xMin, yMin, xMax, yMax;

}

public class Solution {
    final int MAX_CAPACITY =4;
    int level = 0;
    List<Node> nodes;
    Solution northWest = null;
    Solution northEast = null;
    Solution southWest = null;
    Solution southEast = null;
    Boundary boundary;

    Solution(int level, Boundary boundary) {
        this.level = level;
        nodes = new ArrayList<Node>();
        this.boundary = boundary;
    }

    /* Traveling the Graph using Depth First Search*/
    static void dfs(Solution tree) {
        if (tree == null)
            return;

        System.out.printf("\nLevel = %d [X1=%d Y1=%d] \t[X2=%d Y2=%d] ",
                tree.level, tree.boundary.getxMin(), tree.boundary.getyMin(),
                tree.boundary.getxMax(), tree.boundary.getyMax());

        for (Node node : tree.nodes) {
            System.out.printf(" \n\t  x=%d y=%d", node.x, node.y);
        }
        if (tree.nodes.size() == 0) {
            System.out.printf(" \n\t  Leaf Node.");
        }
        dfs(tree.northWest);
        dfs(tree.northEast);
        dfs(tree.southWest);
        dfs(tree.southEast);

    }

    void split() {
        int xOffset = this.boundary.getxMin()
                + (this.boundary.getxMax() - this.boundary.getxMin()) / 2;
        int yOffset = this.boundary.getyMin()
                + (this.boundary.getyMax() - this.boundary.getyMin()) / 2;

        northWest = new Solution(this.level + 1, new Boundary(
                this.boundary.getxMin(), this.boundary.getyMin(), xOffset,
                yOffset));
        northEast = new Solution(this.level + 1, new Boundary(xOffset,
                this.boundary.getyMin(), xOffset, yOffset));
        southWest = new Solution(this.level + 1, new Boundary(
                this.boundary.getxMin(), xOffset, xOffset,
                this.boundary.getyMax()));
        southEast = new Solution(this.level + 1, new Boundary(xOffset, yOffset,
                this.boundary.getxMax(), this.boundary.getyMax()));

    }

    void insert(int x, int y, int value) {
        if (!this.boundary.inRange(x, y)) {
            return;
        }

        Node node = new Node(x, y, value);
        if (nodes.size() < MAX_CAPACITY) {
            nodes.add(node);
            return;
        }
        // Exceeded the capacity so split it in FOUR
        if (northWest == null) {
            split();
        }

        // Check coordinates belongs to which partition
        if (this.northWest.boundary.inRange(x, y))
            this.northWest.insert(x, y, value);
        else if (this.northEast.boundary.inRange(x, y))
            this.northEast.insert(x, y, value);
        else if (this.southWest.boundary.inRange(x, y))
            this.southWest.insert(x, y, value);
        else if (this.southEast.boundary.inRange(x, y))
            this.southEast.insert(x, y, value);
        else
            System.out.printf("ERROR : Unhandled partition %d %d", x, y);
    }

    public static void main(String args[]) {
        Solution anySpace = new Solution(1, new Boundary(0, 0, 1000, 1000));
        anySpace.insert(100, 100, 1);
        anySpace.insert(500, 500, 1);
        anySpace.insert(600, 600, 1);
        anySpace.insert(700, 600, 1);
        anySpace.insert(800, 600, 1);
        anySpace.insert(900, 600, 1);
        anySpace.insert(510, 610, 1);
        anySpace.insert(520, 620, 1);
        anySpace.insert(530, 630, 1);
        anySpace.insert(540, 640, 1);
        anySpace.insert(550, 650, 1);
        anySpace.insert(555, 655, 1);
        anySpace.insert(560, 660, 1);
        //Traveling the graph
        Solution.dfs(anySpace);
    }
}