In-place Fisher-Yates shuffle using:
Random.init 42 deterministic seed
let a = Array.of_list xs
for i = n - 1 downto 1 do reverse iteration
let j = Random.int (i + 1)
let tmp = a.(i) in
a.(i) <- a.(j);
a.(j) <- tmp
done
Sum is invariant under permutation, so the test value (55 for
[1..10] = 1+2+...+10) verifies the shuffle is a valid permutation
regardless of which permutation the seed yields.
Exercises Random.init / Random.int + Array.of_list / to_list /
length / arr.(i) / arr.(i) <- v + downto loop + multi-statement
sequencing within for-body.
33 baseline programs total.
giles
75a1adbbd5