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YAPC::EU 2018 Glasgow Update!

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Ingy döt Net 2018-08-17 15:15:24 +01:00
parent 22f33d4004
commit 4e2d22a71d
1170 changed files with 15042 additions and 3047 deletions
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42
Task/Knuths-algorithm-S/Java/knuths-algorithm-s-2.java
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@ -7,31 +7,27 @@ interface Function<S, T> {
public class AlgorithmS {
private static final Random rand = new Random();
public static <T> Function<T, List<T>> s_of_n_creator(final int n) {
return new Function<T, List<T>>() {
private List<T> sample = new ArrayList<T>(n);
private int i = 0;
public List<T> call(T item) {
i++;
if (i <= n) {
sample.add(item);
} else if (rand.nextInt(i) < n) {
sample.set(rand.nextInt(n), item);
}
return sample;
}
};
return new Function<T, List<T>>() {
private List<T> sample = new ArrayList<T>(n);
private int i = 0;
public List<T> call(T item) {
if (++i <= n) {
sample.add(item);
} else if (rand.nextInt(i) < n) {
sample.set(rand.nextInt(n), item);
}
return sample;
}
};
}
public static void main(String[] args) {
int[] bin = new int[10];
for (int trial = 0; trial < 100000; trial++) {
Function<Integer, List<Integer>> s_of_n = s_of_n_creator(3);
List<Integer> sample = null;
for (int i = 0; i < 10; i++)
sample = s_of_n.call(i);
for (int s : sample)
bin[s]++;
}
System.out.println(Arrays.toString(bin));
int[] bin = new int[10];
for (int trial = 0; trial < 100000; trial++) {
Function<Integer, List<Integer>> s_of_n = s_of_n_creator(3);
for (int i = 0; i < 9; i++) s_of_n.call(i);
for (int s : s_of_n.call(9)) bin[s]++;
}
System.out.println(Arrays.toString(bin));
}
}