public long Solve()
{
var sum = 0L;
var primes = new Prime(Limit / 2).PrimeList;
var count = primes.Count();
for (var i = 0; i < count; i++)
{
if (primes[i] * primes[i] > Limit)
{
break;
}
for (var j = i + 1; j < count; j++)
{
if (primes[i] * primes[j] > Limit)
{
continue;
}
sum += this.MaxSumLimit(primes[i], primes[j], Limit);
}
}
return sum;
}
// chvilku to trva vypocet
public long Solve()
{
var sum = 0L;
var primes = new Prime(Limit);
for (var number = 2; number <= Limit; number++)
{
sum += primes.Totient(number);
}
return sum;
}
public long Solve()
{
var primes = new Prime(Max);
var radValues = new Dictionary<long, long> { { 1, 1 } };
for (var n = 2; n <= Max; n++)
{
var primeFactorization = primes.GetDecomposition(n);
var product = primeFactorization.Aggregate(1L, (current, p) => current * p.Key);
radValues.Add(n, product);
}
var count = 0;
foreach (var radValue in radValues.OrderBy(t => t.Value).ThenBy(t => t.Key))
{
count++;
if (count == 10000)
return radValue.Key;
}
return 0;
}
public long Solve()
{
var resultsCount = 0;
var primes = new Prime((Limit / 2) + 1).PrimeList;
foreach (var prime1 in primes)
{
foreach (var prime2 in primes)
{
var composite = prime1 * prime2;
if (composite < Limit)
{
resultsCount++;
}
else
{
break;
}
}
}
foreach (var prime in primes)
{
var composite = prime * prime;
if (composite < Limit)
{
resultsCount++;
}
else
{
break;
}
}
return resultsCount / 2;
}