Algos directory is setup.

src/algos/stats.cpp

@@ -0,0 +1,11 @@
+#include "algos/stats.hpp"
+#include <fmt/core.h>
+#include "dbc.hpp"
+
+void Stats::dump(std::string msg)
+{
+  dbc::log(fmt::format("{}: sum: {}, sumsq: {}, n: {}, "
+            "min: {}, max: {}, mean: {}, stddev: {}",
+            msg, sum, sumsq, n, min, max, mean(),
+            stddev()));
+}