2023-07-01 11:58:00 -04:00
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func quickselect(a, k) {
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2023-12-16 21:33:55 -08:00
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var pivot = a.pick
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var left = a.grep{|i| i < pivot}
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var right = a.grep{|i| i > pivot}
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2023-07-01 11:58:00 -04:00
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2023-12-16 21:33:55 -08:00
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given(left.len) { |l|
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when(k) { pivot }
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case(k < l) { __FUNC__(left, k) }
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default { __FUNC__(right, k - l - 1) }
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2023-07-01 11:58:00 -04:00
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}
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}
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2023-12-16 21:33:55 -08:00
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var v = [9, 8, 7, 6, 5, 0, 1, 2, 3, 4]
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say v.range.map{|i| quickselect(v, i)}
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