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0ef26b20f3
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Test, Build, and Deploy / test-build-deploy (push) Failing after 24s
Array-backed binary min-heap with explicit size tracking via ref:
let push a size x =
a.(!size) <- x; size := !size + 1; sift_up a (!size - 1)
let pop a size =
let m = a.(0) in
size := !size - 1;
a.(0) <- a.(!size);
sift_down a !size 0;
m
Push [9;4;7;1;8;3;5;2;6], pop nine times -> 1,2,3,4,5,6,7,8,9.
Fold-as-decimal: ((((((((1*10+2)*10+3)*10+4)*10+5)*10+6)*10+7)*10+8)*10+9 = 123456789.
Tests recursive sift_up + sift_down, in-place array swap,
parent/lchild/rchild index arithmetic, combined push/pop session
with refs.
152 baseline programs total.
48 lines
949 B
OCaml
48 lines
949 B
OCaml
let parent i = (i - 1) / 2
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let lchild i = 2 * i + 1
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let rchild i = 2 * i + 2
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let swap a i j =
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let t = a.(i) in
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a.(i) <- a.(j);
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a.(j) <- t
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let rec sift_up a i =
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if i > 0 && a.(parent i) > a.(i) then begin
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swap a i (parent i);
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sift_up a (parent i)
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end
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let rec sift_down a n i =
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let l = lchild i and r = rchild i in
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let smallest = ref i in
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if l < n && a.(l) < a.(!smallest) then smallest := l;
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if r < n && a.(r) < a.(!smallest) then smallest := r;
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if !smallest <> i then begin
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swap a i !smallest;
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sift_down a n !smallest
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end
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let push a size x =
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a.(!size) <- x;
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size := !size + 1;
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sift_up a (!size - 1)
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let pop a size =
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let m = a.(0) in
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size := !size - 1;
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a.(0) <- a.(!size);
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sift_down a !size 0;
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m
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;;
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let a = Array.make 20 0 in
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let s = ref 0 in
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List.iter (fun x -> push a s x) [9; 4; 7; 1; 8; 3; 5; 2; 6];
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let total = ref 0 in
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for _ = 1 to 9 do
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total := !total * 10 + pop a s
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done;
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!total
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