Задача №32

<?
set_time_limit(0);
$n = 0;
for ($i = 999; $i < 9999; $i++) {
	for ($a = 1; $a <= $i; $a++) {
      $good = false;
      $b = $i / $a;
      if (round($b) == $b) {
         $s = "$a$b$i";
         if (strlen($s) == 9) {
            $good = true;
            for ($x = 1; $x < 10; $x++) {
               if (strpos($s, "$x") === false) {
                  $good = false;
                  break;
               }
            }
            if ($good) {
               $n += $i;
               print "$a * $b = $i
";
               break;
            }
         }
      }
	}
}
print $n;
?>

<?
$found = array();
for($i=11; $i<=99; $i++){
	if($i{1} != '0'){
		for($j=111; $j<=999; $j++){
			if(($j{1} != '0') && ($j{2} != '0')){
				   $n = $i*$j;
				   if($n <= 9999){
						$cnt = count(array_flip(preg_split('//', "0".$n.$i.$j, -1, PREG_SPLIT_NO_EMPTY)));
						if($cnt == 10){
							$found[$n]++;
						}
					}
			}
		}
	}
}
echo array_sum(array_keys($found));
?>   

s = {}
check = lambda i, j: i*j < 10000 and i*j > 1000 and \
               "".join(sorted(str(i)+str(j)+str(i*j))) == "123456789"

for i in xrange(1, 9):
  for j in xrange(1, 9999):
    if check(i, j):
      s[i*j] = i, j
for i in xrange(11, 99):
  for j in xrange(11, 999):
    if check(i, j):
      s[i*j] = i, j

print "\n".join(["%i x %i = %i" % (s[a][0], s[a][1], a) for a in s])
print "Total:", sum(s.keys())

27 x 198 = 5346
42 x 138 = 5796
4 x 1738 = 6952
28 x 157 = 4396
4 x 1963 = 7852
48 x 159 = 7632
39 x 186 = 7254
Total: 45228

>>> def do():
	prods = []
	for n in range(1, 10000):
		if len(str(n))==len(set(str(n))):
			for k in range(2, n**.5+1):
				if len(str(k))==len(set(str(k))) and n%k==0 and len(set(''.join(map(str,(n,k,n/k))).replace('0','')))==9:
					print k,'*',n/k,'=',n
					prods.append(n)
	print sum(set(prods))

	
>>> do()
28 * 157 = 4396
18 * 297 = 5346
27 * 198 = 5346
12 * 483 = 5796
42 * 138 = 5796
4 * 1738 = 6952
39 * 186 = 7254
48 * 159 = 7632
4 * 1963 = 7852
45228

#include <stdio.h>
#include <math.h>
#include <time.h>
int numtomask(int n)
{
 int ans=0;
 {
  while(n)
  {
   ans+=1<<(n%10);
   n/=10;
  }
 }
 return ans;
}

int bitcount(int n) {
/* MIT HAKMEM Count
  works for 32-bit numbers only 
  fix last line for 64-bit numbers */
 int tmp;

 tmp = n — ((n >> 1) & 033333333333)
      — ((n >> 2) & 011111111111);
 return ((tmp + (tmp >> 3)) & 030707070707) % 63;
}

int main ()
{
 int magic_number=0;
 clock_t start, finish;
 start=clock();
 for (int a=1234; a<=9876; a++)
 {
  bool find=false;
  int i=(int)sqrt(float(a)), d1=numtomask(a);
  if (bitcount(d1) != 4)
   continue; // coz it isn't abcd-number
  for (; i>=1 &&! find; i--)
   if (a%i==0)
   {
    int d4 = d1 ^ numtomask(a/i) ^ numtomask(i);
    if (1022 == d4) // ..1111111110 in bin
    {
     magic_number+=a;
     
     find=true;
    }
   }
 }
 finish=clock();
 printf(«%i\n», magic_number);
 printf( «%2.7f seconds\n», (double)(finish — start) / CLOCKS_PER_SEC);
 return 0;
}

# Python
import timeit

def gen_positional_combinations(seq, n):
    # Генерируем сочетания по n элементов, только позиционные.
    # Не помню, как это называется в комбинаторике.
    if n==1:
        for e in seq:
            yield e
    else:
        for i in range(len(seq)):
            for tail in gen_positional_combinations(seq[:i]+seq[i+1:], n-1):
                yield seq[i]+tail
    
def work():
    result_set=set()
    for perm in gen_positional_combinations('123456789', 5):
        for i in (1,2):
            x, y = int(perm[:i]), int(perm[i:])
            xy = x*y
            if ''.join(sorted(perm+str(xy)))=='123456789':
                print x, y, x*y 
                result_set.add(x*y)
    return sum(list(result_set))
t = timeit.Timer('print euler32.work()', 'import euler32')
print "Done 10 times in %s sec."%t.timeit(10)

import Data.List (sort, nub)

main = print $ sum $ nub [i | i <- [1234..9876], j <- [2..iSqrt i], let (d,m) = i `divMod` j, m == 0, allDigits i j d]
    where
        iSqrt = round . sqrt . fromIntegral
        allDigits x y z = sort (show x ++ show y ++ show z) == ['1'..'9']