26 lines
820 B
Java
26 lines
820 B
Java
import static java.lang.Math.pow;
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import java.util.*;
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import java.util.function.Function;
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public class Test {
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static double calc(Function<Integer, Integer[]> f, int n) {
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double temp = 0;
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for (int ni = n; ni >= 1; ni--) {
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Integer[] p = f.apply(ni);
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temp = p[1] / (double) (p[0] + temp);
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}
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return f.apply(0)[0] + temp;
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}
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public static void main(String[] args) {
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List<Function<Integer, Integer[]>> fList = new ArrayList<>();
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fList.add(n -> new Integer[]{n > 0 ? 2 : 1, 1});
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fList.add(n -> new Integer[]{n > 0 ? n : 2, n > 1 ? (n - 1) : 1});
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fList.add(n -> new Integer[]{n > 0 ? 6 : 3, (int) pow(2 * n - 1, 2)});
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for (Function<Integer, Integer[]> f : fList)
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System.out.println(calc(f, 200));
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}
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}
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