Additive primes: Difference between revisions

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=={{header|Seed7}}==

<lang seed7>$ include "seed7_05.s7i";

const func boolean: isPrime (in integer: number) is func

result

var boolean: prime is FALSE;

local

var integer: upTo is 0;

var integer: testNum is 3;

begin

if number = 2 then

prime := TRUE;

elsif odd(number) and number > 2 then

upTo := sqrt(number);

while number rem testNum <> 0 and testNum <= upTo do

testNum +:= 2;

end while;

prime := testNum > upTo;

end if;

end func;

const func integer: digitSum (in var integer: number) is func

result

var integer: sum is 0;

begin

while number > 0 do

sum +:= number rem 10;

number := number div 10;

end while;

end func;

const proc: main is func

local

var integer: n is 0;

var integer: count is 0;

begin

for n range 2 to 499 do

if isPrime(n) and isPrime(digitSum(n)) then

write(n lpad 3 <& " ");

incr(count);

if count rem 9 = 0 then

writeln;

end if;

end if;

end for;

writeln("\nFound " <& count <& " additive primes < 500.");

end func;</lang>

{{out}}

<pre>

2 3 5 7 11 23 29 41 43

47 61 67 83 89 101 113 131 137

139 151 157 173 179 191 193 197 199

223 227 229 241 263 269 281 283 311

313 317 331 337 353 359 373 379 397

401 409 421 443 449 461 463 467 487

Found 54 additive primes < 500.