C++ (Cpp) digits_in Examples

Example #1

File: eul38.cpp Project: cslarsen/project-euler

xint pandigit_mul_concat(xint n)
{
	xint i=1;
	xint p=0;

	while ( !pandigital1to9_p(p) && digits_in(p)<10 ) {
		xint next = n * i;
		if ( p>0 ) p *= power(10, digits_in(next));
		p += next;
		++i;
	}

	return p;
}

Example #2

File: eul38.cpp Project: cslarsen/project-euler

int main()
{
	xint max = 0;
	for ( xint n=1; ; ++n ) {
		xint p = pandigit_mul_concat(n);

		if ( !pandigital1to9_p(p) || digits_in(p) > 9 )
			continue;

		if ( digits_in(n) > 4 )
			break;

		if ( p > max ) {
			max = p;
			printf("-- %s for n=%s\n", str(max), str(n));
		}
	}
	printf("end\n");
}

Example #3

File: stringfunc.cpp Project: Adapts/SimpleEdi

int digits_in(int num)
{
  if (num == 0) {
    return 1; // log10() chokes on 0
  }
  if (num < 0) {
    return 1 + digits_in(0 - num);  // 1 extra for the - character
  }

  return 1 + log10(num);  // 1 extra since log10 is logarythmic
}