On Tuesday, 10 March 2015 at 20:41:14 UTC, Dennis Ritchie wrote:
Hi.
How to parallelize a large array to check for the presence of
an element matching the value with the data?
std.stdio;
std.algorithm;
std.parallelism;
You forgot a couple "import"s here.
void main() {
int[] a = new int[1000000];
foreach (i, ref elem; a)
elem = i;
Type mismatch here. i is a size_t, but elem is an int.
/*if (find(parallel(a), 895639).length != 0)
writeln("Yes");
else
writeln("No");*/
}
I guess you'd have to write your own "find". Since
std.algorithm.find is just linear search, that shouldn't be hard.
Something like this:
bool found = false;
foreach(x; parallel(a))
{
if(x == 895639)
{
found = true;
/* Maybe figure out how to break all parallel loops. */
}
}
std.algorithm.find would work on mere input ranges, and it would
return the tail of the range and not just a bool. Both of those
don't make sense with a parallel search, though.
Also, with a trivial predicate like integer equality,
parallelization might not buy you anything.
