On Saturday, 11 September 2021 at 19:37:42 UTC, Vino wrote:
Hi All,
Request your help on the below to print the below array as
"Required output", Was able to get these values
"[1,2],[2,3],[3,4],[4,5]" by using list.slide(2), need your
help to get values "1,3],[1,4],[1,5],[2,4],[2,5],[3,5]"
auto list[] = [1,2,3,4,5]
Required output
[1,2],[2,3],[3,4],[4,5],[1,3],[1,4],[1,5],[2,4],[2,5],[3,5]
From,
Vino
Would this be a valid solution to your problem?
```D
pure @safe nothrow
T[][] computeChoices(T)(T[] values, size_t tupleSize = 2)
{
if (tupleSize == 0) {
return [[]];
}
T[][] choices = [];
tupleSize--;
foreach(i, element; values[0 .. $ - tupleSize])
{
import std.algorithm.iteration : map;
import std.array : array;
choices ~= computeChoices(values[i+1 .. $], tupleSize)
.map!(choice => element ~ choice)
.array;
}
return choices;
}
unittest
{
assert(computeChoices([1, 2, 3, 4, 5], 2)
== [[1,2], [1,3], [1,4], [1,5], [2,3], [2,4], [2,5],
[3,4], [3,5], [4,5]] );
}
```
You can choose in the 2nd parameter how large the inner arrays
should be. It uses GC to allocate the result via the function
`array`. If that is a problem, you could choose an allocator from
`std.experimental.allocator` and use the `makeArray` function
with the allocator instead of the `array` function. (Manual
deallocation could be required then as well.)
