31 lines
681 B
D
31 lines
681 B
D
import std.stdio, std.random;
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auto sofN_creator(in int n) {
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size_t i;
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int[] sample;
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return (in int item) {
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i++;
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if (i <= n)
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sample ~= item;
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else if (uniform01 < (double(n) / i))
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sample[uniform(0, n)] = item;
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return sample;
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};
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}
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void main() {
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enum nRuns = 100_000;
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size_t[10] bin;
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foreach (immutable trial; 0 .. nRuns) {
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immutable sofn = sofN_creator(3);
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int[] sample;
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foreach (immutable item; 0 .. bin.length)
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sample = sofn(item);
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foreach (immutable s; sample)
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bin[s]++;
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}
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writefln("Item counts for %d runs:\n%s", nRuns, bin);
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}
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