RosettaCodeData/Task/Knuths-algorithm-S/Mathematica/knuths-algorithm-s.math

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ClearAll[sofncreator]
sofncreator[n_] := Module[{sample, i},
sample = {};
i = 0;
Return[
Function[{item},
i++;
If[i <= n,
AppendTo[sample, item]
,
If[RandomInteger[{1, i}] <= n,
sample[[RandomInteger[{1, n}]]] = item
]
];
sample
]
]
]
bin = ConstantArray[0, 10];
items = Range[10];
sofn = sofncreator[3];
Do[
sample = sofn[item];
Print[" Item: ", item, " -> sample: " , sample]
,
{item, items}
]
Do[
sofn = sofncreator[3];
Do[
sample = sofn[item]
,
{item, items}
];
Do[
bin[[s]] += 1
,
{s, sample}
]
,
{trial, 100000}
];
{Range[Length[bin]], bin} // Transpose // Grid