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Benchmark: timing 1000000 iterations of iterative_c, iterative_p, recu
+rsive_c, recursive_p...
iterative_c: 1 wallclock secs ( 1.10 usr + 0.00 sys = 1.10 CPU) @ 9
+07441.02/s (n=1000000)
...
iterative_p 51235/s 86% -- -94% -94%
recursive_c 860585/s 3021% 1580% -- -5%
iterative_c 907441/s 3191% 1671% 5% --