poj 1915 KnightMoves(bfs)

import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

public class Main {
    
    static int chessLength;
    
    static int dx[] = {-2, -2, -1, -1, 1, 1, 2, 2};
    static int dy[] = {1, -1, 2, -2, 2, -2, 1, -1};
    
    static Point original, goal;
    
    static Queue<Point> queue;
    
    static boolean marked[][];
    
    static int steps[][];
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int testNumber = sc.nextInt();
        
        for(int i = 1; i <= testNumber; i++) {
            chessLength = sc.nextInt();
            original = new Point(sc.nextInt(), sc.nextInt());
            goal = new Point(sc.nextInt(), sc.nextInt());
            marked = new boolean[chessLength][chessLength];
            steps = new int[chessLength][chessLength];
            queue = new LinkedList<Point> ();
            bfs();
            System.out.println(steps[goal.row][goal.col]);
        }
    }
    
    public static void bfs() {
        queue.add(original);
        marked[original.row][original.col] = true;
        steps[original.row][original.col] = 0;
        
        while(!queue.isEmpty()) {
            Point head = queue.poll();
            for(int i = 0; i < 8; i++) {
                int _row = head.row + dy[i];
                int _col = head.col + dx[i];
                if(_row >= 0 && _row < chessLength && _col >= 0 && _col < chessLength && !marked[_row][_col]) {
                    queue.add(new Point(_row, _col));
                    marked[_row][_col] = true;
                    steps[_row][_col] = steps[head.row][head.col] + 1;
                }
            }
            if(marked[goal.row][goal.col])
                return;
        }
    }
}

class Point {
    int row;
    int col;
    public Point(int row, int col) {
        this.row = row;
        this.col = col;
    }
}