added EAN validator

EANValidator/EANValidator.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.32112.339
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "EANValidator", "EANValidator\EANValidator.csproj", "{6FB2C33C-C18F-425A-BE4C-9176F622EA7C}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{6FB2C33C-C18F-425A-BE4C-9176F622EA7C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6FB2C33C-C18F-425A-BE4C-9176F622EA7C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6FB2C33C-C18F-425A-BE4C-9176F622EA7C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6FB2C33C-C18F-425A-BE4C-9176F622EA7C}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {05DCC730-96C0-43C6-A882-F091287D481B}
+	EndGlobalSection
+EndGlobal

EANValidator/EANValidator/EANValidator.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

EANValidator/EANValidator/Program.cs

@@ -0,0 +1,70 @@
+// See https://aka.ms/new-console-template for more information
+Console.WriteLine("Hello, World!");
+
+
+
+while (true)
+{
+    string mode = "NULL"; int givenCheckNo = 0;
+
+    Console.Write("Pls input complete EAN:\n-> ");
+    string input = Console.ReadLine();
+
+    if (input == "q")
+    {
+        Console.WriteLine("Bye bye!");
+        return;
+    }
+
+    if (input == null || input == "") continue;
+
+    string[] split = input.Select(x => x.ToString()).ToArray();
+
+    if (split.Count() == 13) mode = "VALIDATE";
+    if (split.Count() == 12) mode = "GENERATE";
+
+    if (mode == "NULL") continue;
+
+    bool skip = false;
+    int sum = 0;
+
+    for (int i = 0; i < split.Count(); i++)
+    {
+        string sign = split[i];
+        int val;
+
+        if (!int.TryParse(sign, out val))
+        {
+            break;
+        }
+
+        Console.WriteLine($"no: {val} | sum: {sum}");
+
+        if (i == 12) givenCheckNo = val;
+
+        if (i % 2 == 1)
+        {
+            val *= 3;
+        }
+
+        if (i < 12) sum += val;
+    }
+    if (skip) continue;
+
+    int temp = Convert.ToInt32(Math.Ceiling(sum / 10f));
+
+    int nextFullTen = temp * 10;
+
+    int checksum = nextFullTen - sum;
+
+    string msg = $"Generated Checksum: {checksum}";
+
+    if (mode== "VALIDATE")
+    {
+        msg += $"\nGiven Checksum: {givenCheckNo}";
+        msg += $"\nThey do{(givenCheckNo == checksum ? "" : "n't")} match";
+    }
+
+    Console.WriteLine(msg);
+}
+