Equal prime and composite sums: Difference between revisions

Line 60:

See [[Erdős-primes#jq]] for a suitable definition of `is_prime` as used here.

The program given in this entry requires foreknowledge of the appropriate size of the Eratosthenes sieve.

The program given in this entry requires foreknowledge of the appropriate size of the (virtual) Eratosthenes sieve.

<lang jq>def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] +.;

<lang jq>def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] +.;

def primeSieve: [range(0;.) | if is_prime then . else false end];

def task($sievesize):

{compSums:[],

($sievesize | primeSieve) as $p

| ~~{compSums~~:[0],

primeSums:[],

~~primeSums~~:[],

csum:0,

~~csum~~:0,

psum:0 }

| reduce range(2; $sievesize) as $i (.;

if ~~$p[~~$i~~] == false~~

if $i|is_prime

then .~~csum~~ += $i

then .psum += $i

| .primeSums += [.psum]

else .csum += $i

| .compSums += [ .csum ]

else

.~~psum~~ += $i

| .primeSums += [.psum]

end)

| range(0; .primeSums|length) as $i

Line 83:

Line 80:

| (.compSums | index( $ps )) as $ix

| select($ix >= 0)

| "\($ps|lpad(21)) - \($i+1|lpad(21)) prime sum, \($ix|lpad(12)) composite sum"

| "\($ps|lpad(21)) - \($i+1|lpad(21)) prime sum, \($ix+1|lpad(12)) composite sum"

;