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jianminchen/queensAttackII_codereview.cs

Created January 30, 2017 19:00
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  1. jianminchen created this gist Jan 30, 2017.
    102 changes: 102 additions & 0 deletions queensAttackII_codereview.cs
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    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;

    namespace QueenAttackII
    {
    /*
    * January 30, 2017
    * problem statement:
    * https://www.hackerrank.com/contests/world-codesprint-9/challenges/queens-attack-2
    *
    * study code:
    * facebook - quimey - python
    */
    public class Directions
    {
    // start from left, clockwise, left up, up, right up, right, ...
    public static int[] directions_row = new int[] { 0, 1, 1, 1, 0, -1, -1, -1 };
    public static int[] directions_col = new int[] { -1, -1, 0, 1, 1, 1, 0, -1 };

    public int rows { get; set; }

    public Tuple<int, int> queen { set; get; }

    public Directions(int row, int col, int size)
    {
    queen = new Tuple<int, int>(row, col);

    rows = size;
    }

    public int CalculateTotal(Tuple<int, int>[] obstacles)
    {
    // put all obstacles in a hashset
    HashSet<string> obstacleHashed = new HashSet<string>();
    foreach (Tuple<int, int> obstacle in obstacles)
    {
    obstacleHashed.Add(PrepareKey(obstacle.Item1, obstacle.Item2));
    }

    // go over each direction
    int count = 0;

    for (int i = 0; i < 8; i++)
    {
    int rowIncrement = directions_row[i];
    int colIncrement = directions_col[i];

    int runnerRow = queen.Item1 + rowIncrement;
    int runnerCol = queen.Item2 + colIncrement;

    while( runnerRow >= 0 && runnerRow < rows &&
    runnerCol >= 0 && runnerCol < rows &&
    !obstacleHashed.Contains(PrepareKey(runnerRow, runnerCol)))
    {
    runnerRow += rowIncrement;
    runnerCol += colIncrement;

    count++;
    }
    }

    return count;
    }

    private string PrepareKey(int row, int col)
    {
    return row + "," + col;
    }
    }

    class Program
    {
    static void Main(string[] args)
    {
    ProcessInput();
    }

    public static void ProcessInput()
    {
    int[] data = Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);

    int rows = data[0];
    int countObstacles = data[1];

    int[] queen = Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
    var obstacles = new Tuple<int, int>[countObstacles];

    for (int i = 0; i < countObstacles; i++)
    {
    int[] obstacle = Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
    obstacles[i] = new Tuple<int, int>(obstacle[0] - 1, obstacle[1] - 1);
    }

    Directions directions = new Directions(queen[0] - 1, queen[1] - 1, rows);
    Console.WriteLine(directions.CalculateTotal(obstacles));
    }

    }
    }