move dmath, dsafe and nixctor to snippets/ directory

snippets/dmath/factors.d

@@ -0,0 +1,33 @@
+import std.conv : to;
+import std.stdio : stderr, write, writeln;
+
+int
+main(string[] args)
+{
+	int n;
+
+	if (args.length == 1) {
+		stderr.writeln("usage: factors.d number");
+		return 1;
+	}
+
+	n = args[1].to!int();
+	foreach (int factor; factorsOf(n)) {
+		writeln(factor);
+	}
+
+	return 0;
+}
+
+int[]
+factorsOf(int x)
+{
+	int[] a;
+
+	foreach (int i; 1 .. x + 1) {
+		if (x % i == 0)
+			a ~= i;
+	}
+
+	return a;
+}