38 lines
909 B
Java
38 lines
909 B
Java
import java.util.*;
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interface Function<S, T> {
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public T call(S x);
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}
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public class AlgorithmS {
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private static final Random rand = new Random();
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public static <T> Function<T, List<T>> s_of_n_creator(final int n) {
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return new Function<T, List<T>>() {
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private List<T> sample = new ArrayList<T>(n);
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private int i = 0;
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public List<T> call(T item) {
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i++;
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if (i <= n) {
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sample.add(item);
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} else if (rand.nextInt(i) < n) {
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sample.set(rand.nextInt(n), item);
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}
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return sample;
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}
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};
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}
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public static void main(String[] args) {
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int[] bin = new int[10];
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for (int trial = 0; trial < 100000; trial++) {
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Function<Integer, List<Integer>> s_of_n = s_of_n_creator(3);
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List<Integer> sample = null;
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for (int i = 0; i < 10; i++)
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sample = s_of_n.call(i);
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for (int s : sample)
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bin[s]++;
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}
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System.out.println(Arrays.toString(bin));
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}
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}
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