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labs/lab7_done/Progrssion/GeometricProgression.cs

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+using System;
+
+class GeometricProgression : Progression
+{
+    private int p0;
+    private int q;
+
+    public GeometricProgression(int p0, int q)
+    {
+        this.p0 = p0;
+        this.q = q;
+    }
+
+    public override int GetElement(int k)
+    {
+        return p0 * (int)Math.Pow(q, k - 1);
+    }
+
+    public override int Sum(int n)
+    {
+        if (q == 1) return p0 * n;
+        return p0 * (int)((Math.Pow(q, n) - 1) / (q - 1));
+    }
+}