RosettaCodeData/Task/Tau-number/D/tau-number.d
2023-07-01 13:44:08 -04:00

37 lines
813 B
D

import std.stdio;
uint divisor_count(uint n) {
uint total = 1;
// Deal with powers of 2 first
for (; (n & 1) == 0; n >>= 1) {
++total;
}
// Odd prime factors up to the square root
for (uint p = 3; p * p <= n; p += 2) {
uint count = 1;
for (; n % p == 0; n /= p) {
++count;
}
total *= count;
}
// If n > 1 then it's prime
if (n > 1) {
total *= 2;
}
return total;
}
void main() {
immutable limit = 100;
writeln("The first ", limit, " tau numbers are:");
uint count = 0;
for (uint n = 1; count < limit; ++n) {
if (n % divisor_count(n) == 0) {
writef("%6d", n);
++count;
if (count % 10 == 0) {
writeln;
}
}
}
}