YAPC::EU 2018 Glasgow Update!

Task/Knuths-algorithm-S/Java/knuths-algorithm-s-1.java

@@ -6,32 +6,30 @@ class SOfN<T> {
     private List<T> sample;
     private int i = 0;
     private int n;
+
     public SOfN(int _n) {
-	n = _n;
-	sample = new ArrayList<T>(n);
+        n = _n;
+        sample = new ArrayList<T>(n);
     }
+
     public List<T> process(T item) {
-	i++;
-	if (i <= n) {
+        if (++i <= n) {
             sample.add(item);
-	} else if (rand.nextInt(i) < n) {
-	    sample.set(rand.nextInt(n), item);
-	}
-	return sample;
+        } else if (rand.nextInt(i) < n) {
+            sample.set(rand.nextInt(n), item);
+        }
+        return sample;
     }
 }
 
 public class AlgorithmS {
     public static void main(String[] args) {
-	int[] bin = new int[10];
-	for (int trial = 0; trial < 100000; trial++) {
-	    SOfN<Integer> s_of_n = new SOfN<Integer>(3);
-	    List<Integer> sample = null;
-	    for (int i = 0; i < 10; i++)
-		sample = s_of_n.process(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++) {
+            SOfN<Integer> s_of_n = new SOfN<Integer>(3);
+            for (int i = 0; i < 9; i++) s_of_n.process(i);
+            for (int s : s_of_n.process(9)) bin[s]++;
+        }
+        System.out.println(Arrays.toString(bin));
     }
 }

Task/Knuths-algorithm-S/Java/knuths-algorithm-s-2.java

@@ -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));
     }
 }

Task/Knuths-algorithm-S/Kotlin/knuths-algorithm-s-1.kotlin

@@ -1,16 +1,14 @@
-// version 1.1.2
+// version 1.2.51
 
 import java.util.Random
 
+val rand = Random()
+
 class SOfN<T>(val n: Int) {
     private val sample = ArrayList<T>(n)
     private var i = 0
 
-    private companion object {
-        val rand = Random()
-    }
-
-    fun process(item: T): ArrayList<T> {
+    fun process(item: T): List<T> {
         if (++i <= n)
             sample.add(item)
         else if (rand.nextInt(i) < n)
@@ -23,9 +21,8 @@ fun main(args: Array<String>) {
     val bin = IntArray(10)
     (1..100_000).forEach {
         val sOfn = SOfN<Int>(3)
-        var sample: ArrayList<Int>? = null
-        for (i in 0..9) sample = sOfn.process(i)
-        for (s in sample!!) bin[s]++
+        for (d in 0..8) sOfn.process(d)
+        for (s in sOfn.process(9)) bin[s]++
     }
     println(bin.contentToString())
 }

Task/Knuths-algorithm-S/Kotlin/knuths-algorithm-s-2.kotlin

@@ -0,0 +1,27 @@
+// version 1.2.51
+
+import java.util.Random
+
+val rand = Random()
+
+fun <T> SOfNCreator(n: Int): (T) -> List<T> {
+    val sample = ArrayList<T>(n)
+    var i = 0
+    return {
+        if (++i <= n)
+            sample.add(it)
+        else if (rand.nextInt(i) < n)
+            sample[rand.nextInt(n)] = it
+        sample
+    }
+}
+
+fun main(args: Array<String>) {
+    val bin = IntArray(10)
+    (1..100_000).forEach {
+        val sOfn = SOfNCreator<Int>(3)
+        for (d in 0..8) sOfn(d)
+        for (s in sOfn(9)) bin[s]++
+    }
+    println(bin.contentToString())
+}

Task/Knuths-algorithm-S/Phix/knuths-algorithm-s-1.phix

@@ -0,0 +1,44 @@
+enum RID, I, SAMPLE
+
+function s_of_n(sequence env, integer item)
+    integer i = env[I] + 1,
+            n = length(env[SAMPLE])
+    env[I] = i
+    if i<=n then
+        env[SAMPLE][i] = item
+    elsif n/i>rnd() then
+        env[SAMPLE][rand(n)] = item
+    end if
+    return env
+end function
+
+function s_of_n_creator(int n)
+    return {routine_id("s_of_n"),0,repeat(0,n)}
+end function
+
+function invoke(sequence env, args)
+    env = call_func(env[RID],prepend(args,env))
+    return env
+end function
+
+function test(integer n, sequence items)
+    sequence env = s_of_n_creator(n)
+    for i=1 to length(items) do
+--      env = s_of_n(env,items[i])
+        env = invoke(env, {items[i]})
+    end for
+    return env[SAMPLE]
+end function
+
+procedure main()
+    sequence items_set = tagset(9,0)
+    sequence frequencies = repeat(0,length(items_set))
+    for i=1 to 100000 do
+        sequence res = test(3, items_set)
+        for j=1 to length(res) do
+            frequencies[res[j]+1] += 1
+        end for
+    end for
+    ?frequencies
+end procedure
+main()

Task/Knuths-algorithm-S/Phix/knuths-algorithm-s-2.phix

@@ -0,0 +1,9 @@
+enum RID, I, SAMPLE, CLOSURE_LEN=$
+...
+function s_of_n_creator(int n)
+    sequence closure = repeat(0,CLOSURE_LEN)
+    closure[RID] = routine_id("s_of_n")
+    closure[I] = 0
+    closure[SAMPLE] = repeat(0,n)
+    return closure
+end function