Data commit

Task/Catalan-numbers/Vala/catalan-numbers.vala

@@ -0,0 +1,77 @@
+namespace CatalanNumbers {
+  public class CatalanNumberGenerator {
+    private static double factorial(double n) {
+      if (n == 0)
+        return 1;
+      return n * factorial(n - 1);
+    }
+
+    public double first_method(double n) {
+      const double top_multiplier = 2;
+      return factorial(top_multiplier * n) / (factorial(n + 1) * factorial(n));
+    }
+
+    public double second_method(double n) {
+      if (n == 0) {
+        return 1;
+      }
+      double sum = 0;
+      double i = 0;
+      for (; i <= (n - 1); i++) {
+        sum += second_method(i) * second_method((n - 1) - i);
+      }
+      return sum;
+    }
+
+    public double third_method(double n) {
+      if (n == 0) {
+        return 1;
+      }
+      return ((2 * (2 * n - 1)) / (n + 1)) * third_method(n - 1);
+    }
+  }
+
+  void main() {
+    CatalanNumberGenerator generator = new CatalanNumberGenerator();
+    DateTime initial_time;
+    DateTime final_time;
+    TimeSpan ts;
+
+    stdout.printf("Direct Method\n");
+    stdout.printf(" n%9s\n", "C_n");
+    stdout.printf("............\n");
+    initial_time = new DateTime.now();
+    for (double i = 0; i <= 15; i++) {
+      stdout.printf("%2s %8s\n", i.to_string(), Math.ceil(generator.first_method(i)).to_string());
+    }
+    final_time = new DateTime.now();
+    ts = final_time.difference(initial_time);
+    stdout.printf("............\n");
+    stdout.printf("Time Elapsed: %s μs\n", ts.to_string());
+
+    stdout.printf("\nRecursive Method 1\n");
+    stdout.printf(" n%9s\n", "C_n");
+    stdout.printf("............\n");
+    initial_time = new DateTime.now();
+    for (double i = 0; i <= 15; i++) {
+      stdout.printf("%2s %8s\n", i.to_string(), Math.ceil(generator.second_method(i)).to_string());
+    }
+    final_time = new DateTime.now();
+    ts = final_time.difference(initial_time);
+    stdout.printf("............\n");
+    stdout.printf("Time Elapsed: %s μs\n", ts.to_string());
+
+    stdout.printf("\nRecursive Method 2\n");
+    stdout.printf(" n%9s\n", "C_n");
+    stdout.printf("............\n");
+    initial_time = new DateTime.now();
+    for (double i = 0; i <= 15; i++) {
+      stdout.printf("%2s %8s\n", i.to_string(), Math.ceil(generator.third_method(i)).to_string());
+    }
+    final_time = new DateTime.now();
+    ts = final_time.difference(initial_time);
+    stdout.printf("............\n");
+    stdout.printf("Time Elapsed: %s μs\n", ts.to_string());
+
+  }
+}