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std.algorithm.sorting.topN - multiple declarations
Function topN
Reorders the range r using swap such that r[nth] refers
to the element that would fall there if the range were fully
sorted. In addition, it also 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 satisfy
!less(e2, r[nth]). Effectively, it finds the nth smallest
(according to less) elements in r. Performs an expected
Ο(r) (if unstable) or Ο(r)
(if stable) evaluations of less and swap.
auto auto topN(alias less, SwapStrategy ss = SwapStrategy
Range r,
size_t nth
)
if (isRandomAccessRange!Range && hasLength!Range && hasSlicing!Range && hasAssignableElements!Range);
If n >= r, the algorithm has no effect and returns
r[0 .. r.
Parameters
| Name | Description |
|---|---|
| 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. |
See Also
BUGS
Stable topN has not been implemented yet.
Example
int[] v = [ 25, 7, 9, 2, 0, 5, 21 ];
topN!"a < b"(v, 100);
writeln(v); // [25, 7, 9, 2, 0, 5, 21]
auto n = 4;
topN!((a, b) => a < b)(v, n);
writeln(v[n]); // 9
Function topN
Stores the smallest elements of the two ranges in the left-hand range.
auto auto topN(alias less, SwapStrategy ss = SwapStrategy
Range1 r1,
Range2 r2
)
if (isRandomAccessRange!Range1 && hasLength!Range1 && isInputRange!Range2 && is(ElementType!Range1 == ElementType!Range2) && hasLvalueElements!Range1 && hasLvalueElements!Range2);
Parameters
| Name | Description |
|---|---|
| less | The predicate to sort by. |
| ss | The swapping strategy to use. |
| r1 | The first range. |
| r2 | The second range. |
Example
int[] a = [ 5, 7, 2, 6, 7 ];
int[] b = [ 2, 1, 5, 6, 7, 3, 0 ];
topN(a, b);
sort(a);
writeln(a); // [0, 1, 2, 2, 3]
Authors
License
Copyright © 1999-2022 by the D Language Foundation | Page generated by ddox.