dmath: init directory

dmath/isfactor.d

@@ -0,0 +1,29 @@
+import std.conv : to;
+import std.stdio : stderr, writeln;
+
+int
+main(string[] args)
+{
+	int f, i, n;
+
+	if (args.length < 3) {
+		stderr.writeln("usage: isfactor.d fac num");
+		return 1;
+	}
+
+	f = args[1].to!int();
+	n = args[2].to!int();
+
+	i = f;
+	while (i < n) {
+		i += f;
+	}
+
+	if (i == n) {
+		writeln(f, " is a factor of ", n);
+		return 0;
+	}
+
+	writeln(f, " is NOT a factor of ", n);
+	return 1;
+}