r[0] to r[nth], excluding r[nth] itself.topN
fn
auto topN(alias less = "a < b",
SwapStrategy ss = SwapStrategy.unstable,
Range)(Range r, size_t nth) if (isRandomAccessRange!(Range) && hasLength!Range &&
hasSlicing!Range && hasAssignableElements!Range)Reorders the range r using swap such that r[nth] refers to the element that would fall there if the range were fully sorted.
It is akin to Quickselect, and partitions r such that all elements e1 from r[0] to r[nth] satisfy !less(r[nth], e1), and all elements e2 from r[nth] to r[r.length] satisfy !less(e2, r[nth]). Effectively, it finds the nth + 1 smallest (according to less) elements in r. Performs an expected r.length (if unstable) or r.length * log(r.length) (if stable) evaluations of less and swap.
If n >= r.length, the algorithm has no effect and returns r[0 .. r.length].
Parameters
less | The predicate to sort by. |
ss | The swapping strategy to use. |
r | The random-access range to reorder. |
nth | The index of the element that should be in sorted position after the function is done. |
Returns
a slice from
See Also
fn
auto topN(alias less = "a < b",
SwapStrategy ss = SwapStrategy.unstable,
Range1, Range2)(Range1 r1, Range2 r2) if (isRandomAccessRange!(Range1) && hasLength!Range1 &&
isInputRange!Range2 && is(ElementType!Range1 == ElementType!Range2) &&
hasLvalueElements!Range1 && hasLvalueElements!Range2)Stores the smallest elements of the two ranges in the left-hand range.
Parameters
less | The predicate to sort by. |
ss | The swapping strategy to use. |
r1 | The first range. |
r2 | The second range. |