giles
89a807a1ed
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Test, Build, and Deploy / test-build-deploy (push) Failing after 22s
collatz_len walks n through n/2 if even, 3n+1 if odd, counting
steps. Outer loop scans 2..N tracking the best length and arg-best:
let euler14 limit =
let best = ref 0 in
let best_n = ref 0 in
for n = 2 to limit do
let l = collatz_len n in
if l > !best then begin
best := l;
best_n := n
end
done;
!best_n
euler14 100 = 97 (97 generates a 118-step chain)
Real PE14 uses limit = 1_000_000 (answer 837799); 100 exercises the
same algorithm in <2 minutes on our contended host.
116 baseline programs total.
26 lines
394 B
OCaml
26 lines
394 B
OCaml
let collatz_len n =
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let m = ref n in
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let c = ref 0 in
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while !m > 1 do
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if !m mod 2 = 0 then m := !m / 2
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else m := 3 * !m + 1;
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c := !c + 1
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done;
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!c
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let euler14 limit =
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let best = ref 0 in
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let best_n = ref 0 in
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for n = 2 to limit do
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let l = collatz_len n in
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if l > !best then begin
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best := l;
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best_n := n
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end
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done;
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!best_n
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;;
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euler14 100
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