Primes whose sum of digits is 25: Difference between revisions
(Added phix and stretch goal) |
(Added Algol W) |
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;Stretch goal |
;Stretch goal |
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Show the total number of all such primes that do not contain any zeroes. |
Show the total number of all such primes that do not contain any zeroes. |
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=={{header|ALGOL W}}== |
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<lang algolw>begin % find some primes whose digits sum to 25 % |
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% sets p( 1 :: n ) to a sieve of primes up to n % |
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procedure Eratosthenes ( logical array p( * ) ; integer value n ) ; |
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begin |
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p( 1 ) := false; p( 2 ) := true; |
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for i := 3 step 2 until n do p( i ) := true; |
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for i := 4 step 2 until n do p( i ) := false; |
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for i := 3 step 2 until truncate( sqrt( n ) ) do begin |
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integer ii; ii := i + i; |
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if p( i ) then for pr := i * i step ii until n do p( pr ) := false |
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end for_i ; |
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end Eratosthenes ; |
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integer MAX_NUMBER; |
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MAX_NUMBER := 4999; |
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begin |
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logical array prime( 1 :: MAX_NUMBER ); |
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integer pCount; |
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% sieve the primes to MAX_NUMBER % |
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Eratosthenes( prime, MAX_NUMBER ); |
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% find the primes whose digits sum to 25 % |
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pCount := 0; |
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for i := 1 until MAX_NUMBER do begin |
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if prime( i ) then begin |
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integer dSum, v; |
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v := i; |
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dSum := 0; |
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while v > 0 do begin |
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dSum := dSum + ( v rem 10 ); |
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v := v div 10 |
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end while_v_gt_0 ; |
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if dSum = 25 then begin |
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writeon( i_w := 4, s_w := 0, " ", i ); |
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pCount := pCount + 1; |
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if pCount rem 20 = 0 then write() |
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end if_prime_pReversed |
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end if_prime_i |
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end for_i ; |
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write( i_w := 1, s_w := 0, "Found ", pCount, " sum25 primes below ", MAX_NUMBER + 1 ) |
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end |
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end.</lang> |
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{{out}} |
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<pre> |
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997 1699 1789 1879 1987 2689 2797 2887 3499 3697 3769 3877 3967 4597 4759 4957 4993 |
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Found 17 sum25 primes below 5000 |
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</pre> |
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=={{header|Phix}}== |
=={{header|Phix}}== |
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"1 minute and 27s" |
"1 minute and 27s" |
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</pre> |
</pre> |
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=={{header|Ring}}== |
=={{header|Ring}}== |
Revision as of 11:07, 21 March 2021
- Task
Show primes which sum of digits is 25
Let 0 < n < 5000
- Stretch goal
Show the total number of all such primes that do not contain any zeroes.
ALGOL W
<lang algolw>begin % find some primes whose digits sum to 25 %
% sets p( 1 :: n ) to a sieve of primes up to n % procedure Eratosthenes ( logical array p( * ) ; integer value n ) ; begin p( 1 ) := false; p( 2 ) := true; for i := 3 step 2 until n do p( i ) := true; for i := 4 step 2 until n do p( i ) := false; for i := 3 step 2 until truncate( sqrt( n ) ) do begin integer ii; ii := i + i; if p( i ) then for pr := i * i step ii until n do p( pr ) := false end for_i ; end Eratosthenes ; integer MAX_NUMBER; MAX_NUMBER := 4999; begin logical array prime( 1 :: MAX_NUMBER ); integer pCount; % sieve the primes to MAX_NUMBER % Eratosthenes( prime, MAX_NUMBER ); % find the primes whose digits sum to 25 % pCount := 0; for i := 1 until MAX_NUMBER do begin if prime( i ) then begin integer dSum, v; v := i; dSum := 0; while v > 0 do begin dSum := dSum + ( v rem 10 ); v := v div 10 end while_v_gt_0 ; if dSum = 25 then begin writeon( i_w := 4, s_w := 0, " ", i ); pCount := pCount + 1; if pCount rem 20 = 0 then write() end if_prime_pReversed end if_prime_i end for_i ; write( i_w := 1, s_w := 0, "Found ", pCount, " sum25 primes below ", MAX_NUMBER + 1 ) end
end.</lang>
- Output:
997 1699 1789 1879 1987 2689 2797 2887 3499 3697 3769 3877 3967 4597 4759 4957 4993 Found 17 sum25 primes below 5000
Phix
<lang Phix>function sum25(integer p) return sum(sq_sub(sprint(p),'0'))=25 end function sequence res = filter(get_primes_le(5000),sum25) string r = join(shorten(apply(res,sprint),"",4)) printf(1,"%d sum25 primes less than 5000 found: %s\n",{length(res),r})</lang>
- Output:
17 sum25 primes less than 5000 found: 997 1699 1789 1879 ... 4597 4759 4957 4993
Stretch goal <lang Phix>include mpfr.e atom t0 = time(), t1 = time()+1 mpz pz = mpz_init(0)
function sum25(string p, integer rem, res=0)
if rem=0 then if find(p[$],"1379") then -- (saves 13s) mpz_set_str(pz,p) if mpz_prime(pz) then res += 1 if time()>t1 then progress("%d, %s...",{res,p}) t1 = time()+1 end if end if end if else for i=1 to min(rem,9) do res = sum25(p&'0'+i,rem-i,res) end for end if return res
end function
printf(1,"There are %,d sum25 primes that contain no zeroes\n",sum25("",25)) ?elapsed(time()-t0)</lang>
- Output:
There are 1,525,141 sum25 primes that contain no zeroes "1 minute and 27s"
Ring
<lang ring> load "stdlib.ring"
row = 0 limit1 = 25 limit2 = 5000
for n = 1 to limit2
if isprime(n) bool = sum25(n) if bool = 1 row = row + 1 see "" + n + " " if (row%5) = 0 see nl ok ok ok
next
func sum25(n)
sum = 0 str = string(n) for n = 1 to len(str) sum = sum + number(str[n]) next if sum = limit1 return 1 ok
</lang>
- Output:
997 1699 1789 1879 1987 2689 2797 2887 3499 3697 3769 3877 3967 4597 4759 4957 4993