trjhtr

This challenge was pretty simple - be given the coordinates of a king and a queen on a chess board and determine if the king is in check.

Input is the number of test cases with each test case on a new line, king coordinates first. I read in via text file.

Output "Y" or "N" as the result for each test case.

e.g.

input data:
8
b4 b8
b4 e7
b4 d2
b4 g4
f2 b1
f2 c4
f2 d5
f2 g7

answer:
Y Y Y Y N N N N

I tried a bunch of stuff using System.Text.Encoding to try to figure out how to get the ascii char code from my letters, but ended up falling back on to what I know (Microsoft.VisualBasic).

Option Explicit On
Option Strict On
Option Infer On
Option Compare Text

Imports System.IO
Module Module1

 <STAThread>
 Sub Main()
 Const PATH = "C:Tempkingqueen.txt"
 Dim fileContents As String() = System.IO.File.ReadAllLines(PATH)
 Dim numberOfScenarios As Integer = Convert.ToInt32(fileContents(0))
 Dim result As String
 Dim king As String
 Dim queen As String
 For game As Integer = 1 To numberOfScenarios
 king = fileContents(game).Substring(0, 2)
 queen = fileContents(game).Substring(fileContents(game).Length - 2, 2)
 result = result & TestLines(king, queen) & " "
 Next
 result.Trim()
 Console.WriteLine(result)
 End Sub

 Private Function TestLines(ByVal king As String, ByVal queen As String) As String
 Dim kingsub As String = king.Substring(0, 1)
 If king.Substring(0, 1) = queen.Substring(0, 1) Or king.Substring(king.Length - 1, 1) = queen.Substring(queen.Length - 1, 1) Then
 Return "Y"
 Else
 Return TestDiagonals(king, queen)
 End If
 End Function

 Private Function TestDiagonals(ByVal king As String, ByVal queen As String) As String
 Dim kingRank As Integer = Microsoft.VisualBasic.Strings.AscW(king.Substring(0, 1))
 Dim kingFile As Integer = Convert.ToInt32(king.Substring(1, 1))
 Dim queenRank As Integer = Microsoft.VisualBasic.Strings.AscW(queen.Substring(0, 1))
 Dim queenFile As Integer = Convert.ToInt32(queen.Substring(1, 1))

 If (kingRank + kingFile = queenRank + queenFile) Or (kingRank - kingFile = queenRank - queenFile) Then
 Return "Y"
 Else
 Return "N"
 End If
 End Function
End Module 

I would suggest that rather than try parsing strings all through your code, try this.

The code below creates a couple of new things. a numeric coordinate structure, a scenario, which is a pair of coordinates, and a list of scenarios.

There are also a couple of functions to parse the text file and each chess location into coordinates. Further down the line, it makes thing easier when you come to checking the queen and king locations.

Module Module1
 Structure Coord
 Dim Rank As Integer
 Dim File As Integer
 End Structure

 Structure Scenario
 Dim King As Coord
 Dim Queen As Coord
 End Structure

 Dim Scenarios As New List(Of Scenario)
 Dim fileContents() As String
 <STAThread>
 Sub Main()
 Const PATH = "C:Tempkingqueen.txt"
 fileContents = System.IO.File.ReadAllLines(PATH)
 ParseTextFile()
 Dim result As String = ""
 For Each testScenario As Scenario In Scenarios
 result = result & TestLines(testScenario) & " "
 Next
 result.Trim()
 Console.WriteLine(result)
 Console.ReadLine()
 End Sub

 Private Function ParsePieceLocationAsCoord(chessCoord As String) As Coord
 Dim tempPoint As New Coord
 tempPoint.File = Asc(chessCoord(0)) - 96
 tempPoint.Rank = Val(chessCoord(1))
 Return tempPoint
 End Function

 Private Sub ParseTextFile()
 Scenarios.Clear()
 For Each line As String In fileContents
 Dim newScenario As Scenario
 newScenario.King = ParsePieceLocationAsCoord(line.Substring(0, 2))
 newScenario.Queen = ParsePieceLocationAsCoord(line.Substring(3, 2))
 Scenarios.Add(newScenario)
 Next
 End Sub

 Private Function TestLines(testScenario As Scenario) As String
 With testScenario
 If .King.Rank = .Queen.Rank Or .King.File = .Queen.File Then
 Return "Y"
 Else
 Return TestDiagonals(testScenario)
 End If
 End With
 End Function

 Private Function TestDiagonals(testScenario As Scenario) As String
 With testScenario
 If (.King.Rank + .King.File = .Queen.Rank + .Queen.File) Or (.King.Rank - .King.File = .Queen.Rank - .Queen.File) Then
 Return "Y"
 Else
 Return "N"
 End If
 End With
 End Function