tasks a-s

Task/Power-set/D/power-set.d

@@ -0,0 +1,16 @@
+import std.stdio;
+
+T[][] powerSet(T)(in T[] s) pure nothrow {
+    auto r = new typeof(return)(1, 0);
+    foreach (e; s) {
+        typeof(return) rs;
+        foreach (x; r)
+            rs ~= x ~ [e];
+        r ~= rs;
+    }
+    return r;
+}
+
+void main() {
+    writeln(powerSet([1, 2, 3]));
+}