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Perfect totient numbers: Difference between revisions
Added implementation in bc
Deadmarshal (talk | contribs) (Added Lua) |
(Added implementation in bc) |
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Line 545:
return phi
end function</lang>
=={{header|bc}}==
<lang bc>define gcd (i, j) {
while(j != 0) {
k = j
j = i % j
i = k
}
return i
}
define is_perfect_totient (num) {
tot = 0
for (i = 1; i < num; i++) {
if (gcd(num, i) == 1) {
tot += 1
}
}
sum = tot + cache[tot]
cache[num] = sum
return num == sum
}
j = 1
count = 0
# we only go to 15 (not 20) because bc is very slow
while (count <= 15) {
if (is_perfect_totient(j)) {
print j, " "
count += 1
}
j += 1
}
print "\n"
quit
</lang>
{{out}}
<pre>
$ time bc -q perfect-totient.bc
3 9 15 27 39 81 111 183 243 255 327 363 471 729 2187 2199
real 0m35,553s
user 0m35,437s
sys 0m0,030s
</pre>
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