Initial data commit

Task/Knuths-algorithm-S/D/knuths-algorithm-s-1.d

@@ -0,0 +1,30 @@
+import std.stdio, std.random;
+
+auto sofN_creator(in int n) {
+    size_t i;
+    int[] sample;
+
+    return (in int item) {
+        i++;
+        if (i <= n)
+            sample ~= item;
+        else if (uniform01 < (double(n) / i))
+            sample[uniform(0, n)] = item;
+        return sample;
+    };
+}
+
+void main() {
+    enum nRuns = 100_000;
+    size_t[10] bin;
+
+    foreach (immutable trial; 0 .. nRuns) {
+        immutable sofn = sofN_creator(3);
+        int[] sample;
+        foreach (immutable item; 0 .. bin.length)
+            sample = sofn(item);
+        foreach (immutable s; sample)
+            bin[s]++;
+    }
+    writefln("Item counts for %d runs:\n%s", nRuns, bin);
+}