RosettaCodeData/Task/Parallel-calculations/D/parallel-calculations-1.d

28 lines
952 B
D

ulong[] decompose(ulong n) pure nothrow {
typeof(return) result;
for (ulong i = 2; n >= i * i; i++)
for (; n % i == 0; n /= i)
result ~= i;
if (n != 1)
result ~= n;
return result;
}
void main() {
import std.stdio, std.algorithm, std.parallelism, std.typecons;
immutable ulong[] data = [
2UL^^59-1, 2UL^^59-1, 2UL^^59-1, 112_272_537_195_293UL,
115_284_584_522_153, 115_280_098_190_773,
115_797_840_077_099, 112_582_718_962_171,
112_272_537_095_293, 1_099_726_829_285_419];
//auto factors = taskPool.amap!(n => tuple(decompose(n), n))(data);
//static enum genPair = (ulong n) pure => tuple(decompose(n), n);
static genPair(ulong n) pure { return tuple(decompose(n), n); }
auto factors = taskPool.amap!genPair(data);
auto pairs = factors.map!(p => tuple(p[0].reduce!min, p[1]));
writeln("N. with largest min factor: ", pairs.reduce!max[1]);
}