static void Main(string[] args)
{
PrimeGenerator pg = new PrimeGenerator();
int[] primes = pg.GetPrimesBelowOneMillion();
int rlt = 1;
int tmp = 1;
foreach(int p in primes){
tmp = tmp * p;
if (tmp >= NUMCOUNT)
{
break;
}
rlt = tmp;
}
Console.WriteLine(rlt);
}
static void Main(string[] args)
{
PrimeGenerator pg = new PrimeGenerator();
int[] primes = pg.GetPrimesBelowOneMillion();
bool[] primeMark = pg.CheckPrimeNumber(1000000);
for (int i = 0; i < primes.Length; i++)
{
int prime = primes[i];
int[] digits = NumberUtils.SplitNumber(prime,1);
for (int mark = 1; mark < ((1 << digits.Length) - 1); mark++)
{
int primeCount = 0;
for (int n = 0; n < 10; n++)
{
int[] markedDigits = ChangeMarkedDigits(digits, mark, n);
if (markedDigits[0] % 2 == 0 || markedDigits[0] % 5 == 0)
continue;
if (markedDigits[digits.Length - 1] == 0)
continue;
int num = MarkDigitsToNumber(markedDigits);
if (!primeMark[num])
continue;
primeCount++;
}
if (primeCount == 8)
{
int result = int.MaxValue;
for (int n = 0; n < 10; n++)
{
int[] markedDigits = ChangeMarkedDigits(digits, mark, n);
if (markedDigits[0] % 2 == 0 || markedDigits[0] % 5 == 0)
continue;
if (markedDigits[digits.Length - 1] == 0)
continue;
int num = MarkDigitsToNumber(markedDigits);
if (!primeMark[num])
continue;
if (num < result)
result = num;
}
Console.WriteLine("Result is {0}", result);
return;
}
//Console.WriteLine(Convert.ToString(mark, 2));
}
}
}
static void Main(string[] args)
{
for (int i = 0; i < 10000; i++)
{
squares[i * i] = true;
}
squares[0] = false;
PrimeGenerator pg = new PrimeGenerator();
primes = pg.GetPrimesBelowOneMillion();
primeTag = pg.CheckPrimeNumber(1000000);
int squTwice = 0;
int firstOdd = 0;
bool pass = false;
for (int i = 3; ; i += 2)
{
if (primeTag[i])
continue;
pass = false;
foreach (int prime in primes)
{
if (i <= prime)
break;
squTwice = i - prime;
if (squTwice % 2 != 0)
continue;
squTwice = squTwice / 2;
if (!squares[squTwice])
continue;
pass = true;
break;
}
if (pass)
continue;
firstOdd = i;
break;
}
Console.WriteLine(string.Format("Result is {0}", firstOdd));
}