Added exercices

Algorithms/Exercices/FirstSet.cs

@@ -0,0 +1,34 @@
+namespace Algorithms.Exercices;
+
+using System;
+
+class Solutions {
+
+    public static string RemoveTitle(string header)
+    {
+        int idx = header.IndexOf(".");
+        return header.Substring(idx + 1);
+    }
+
+    public static void MainExampleOfRemoveTitle(string[] args){
+        Console.WriteLine(RemoveTitle("4.56.2")); // "56.2"
+        Console.WriteLine(RemoveTitle("4.b.ii")); // "b.ii"
+        Console.WriteLine(RemoveTitle("")); // ""
+        Console.WriteLine(RemoveTitle("4.b")); // "b"
+    }
+
+    public static void PrintEachDirectoryOnPath(string path)
+    {
+        string[] subs = path.Split(':');
+
+        foreach (var sub in subs)
+        {
+            Console.WriteLine(sub);
+        }
+    }
+
+    public static void MainExampleOfPrintEachDirectoryOnPath(String[] args){
+        string? path = Environment.GetEnvironmentVariable("PATH");
+        PrintEachDirectoryOnPath(path ?? "");
+    }
+}