public void Problem41()
{
string numberToPerm = "1";
List <string> permutations = new List <string>();
for (int i = 1; i < 9; i++)
{
int j = i + 1;
numberToPerm += j;
EulerHelperFunctions.GetPermutations(numberToPerm.ToCharArray(), numberToPerm.Length, permutations);
}
long largestPandigital = 0;
foreach (long number in permutations.ConvertAll(x => Int64.Parse(x)).OrderByDescending(x => x))
{
if (EulerHelperFunctions.IsPrime(number))
{
largestPandigital = number;
return;
}
}
Assert.Equal(7652413, largestPandigital);
}
public void Problem6()
{
long sumOfSquares = EulerHelperFunctions.SumOfSquares(100);
long squareOfSums = EulerHelperFunctions.SquareOfSums(100);
Assert.Equal(25164150, squareOfSums - sumOfSquares);
}
public void Problem10()
{
List <long> numbersList = EulerHelperFunctions.CreateListOfNumbers(2000000);
List <long> primes = EulerHelperFunctions.GetPrimeNumbers(numbersList);
Assert.Equal(142913828922, primes.Sum());
}
public void Problem3()
{
List <long> factors = EulerHelperFunctions.GetAllFactors(600851475143);
List <long> primes = EulerHelperFunctions.GetPrimeNumbers(factors);
Assert.Equal(6857, primes.Max());
}
public void Problem1()
{
int maxNumber = 1000;
int[] factors = new int[] { 3, 5 };
Assert.Equal(233168, EulerHelperFunctions.GetMultiples(maxNumber, factors).Sum());
}
public void Problem24()
{
string numberToPerm = "0123456789";
List <string> permutations = new List <string>();
EulerHelperFunctions.GetPermutations(numberToPerm.ToCharArray(), numberToPerm.Length, permutations);
Assert.Equal("2783915460", permutations.OrderBy(x => x).Skip(999999).First());
}
public void Problem5()
{
long number = 1;
long[] factors = new long[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
while (!EulerHelperFunctions.IsMultipleOfAllFactor(number, factors))
{
number++;
}
Assert.Equal(232792560, number);
}
public void Problem21()
{
var sum = 0;
for (int i = 1; i < 10000; i++)
{
if (EulerHelperFunctions.IsAmicable(i))
{
sum = sum + i;
}
}
Assert.Equal(31626, sum);
}
public void Problem12()
{
long n = 1;
long nthTriangularNumber = 1;
List <long> factors = EulerHelperFunctions.GetAllFactors(nthTriangularNumber);
while (factors.Count <= 500)
{
n++;
nthTriangularNumber += n;
factors = EulerHelperFunctions.GetAllFactors(nthTriangularNumber);
}
Assert.Equal(76576500, nthTriangularNumber);
}
public void Problem14()
{
long startNumberForLongestSequence = 0;
long maxLength = 1;
for (long i = 1; i <= 1000000; i++)
{
long newLength = EulerHelperFunctions.GenerateCollatzSequence(i).Count();
if (newLength > maxLength)
{
maxLength = newLength;
startNumberForLongestSequence = i;
}
}
Assert.Equal(837799, startNumberForLongestSequence);
}
public void Problem7()
{
long number = 2;
long counter = 1;
long prime = number;
while (counter <= 10001)
{
if (EulerHelperFunctions.IsPrime(number))
{
counter++;
prime = number;
}
number++;
}
Assert.Equal(104743, prime);
}
public void Problem4()
{
long minNumber = 100;
long maxNumber = 999;
long largestPalindrome = 0;
for (long i = minNumber; i <= maxNumber; i++)
{
for (long j = minNumber; j < maxNumber; j++)
{
largestPalindrome =
(i * j > largestPalindrome && EulerHelperFunctions.IsPalindrome((i * j).ToString()))
? i * j
: largestPalindrome;
}
}
Assert.Equal(906609, largestPalindrome);
}
public void Problem9()
{
int cMax = 998;
int product = 0;
for (int a = 1; a <= cMax - 2; a++)
{
for (int b = a + 1; b <= cMax - 1; b++)
{
for (int c = b + 1; c <= cMax; c++)
{
if (EulerHelperFunctions.IsPythagoreanTriplet((long)a, (long)b, (long)c) && a + b + c == 1000)
{
product = a * b * c;
return;
}
}
}
}
Assert.Equal(31875000, product);
}
public void Problem8()
{
string thousandDigitNumber =
"73167176531330624919225119674426574742355349194934" +
"96983520312774506326239578318016984801869478851843" +
"85861560789112949495459501737958331952853208805511" +
"12540698747158523863050715693290963295227443043557" +
"66896648950445244523161731856403098711121722383113" +
"62229893423380308135336276614282806444486645238749" +
"30358907296290491560440772390713810515859307960866" +
"70172427121883998797908792274921901699720888093776" +
"65727333001053367881220235421809751254540594752243" +
"52584907711670556013604839586446706324415722155397" +
"53697817977846174064955149290862569321978468622482" +
"83972241375657056057490261407972968652414535100474" +
"82166370484403199890008895243450658541227588666881" +
"16427171479924442928230863465674813919123162824586" +
"17866458359124566529476545682848912883142607690042" +
"24219022671055626321111109370544217506941658960408" +
"07198403850962455444362981230987879927244284909188" +
"84580156166097919133875499200524063689912560717606" +
"05886116467109405077541002256983155200055935729725" +
"71636269561882670428252483600823257530420752963450";
int lengthOfNumber = 13;
long sum = 0;
while (thousandDigitNumber.Length > 13)
{
string extractedNumber = thousandDigitNumber.Substring(0, lengthOfNumber);
long currentSum = EulerHelperFunctions.ProductIndividualDigitsInString(extractedNumber);
sum = currentSum > sum ? currentSum : sum;
thousandDigitNumber = thousandDigitNumber.Remove(0, 1);
}
Assert.Equal(23514624000, sum);
}
public void Problem20()
{
string factorialAsString = ((BigInteger)EulerHelperFunctions.Factorial(100)).ToString();
Assert.Equal(648, EulerHelperFunctions.SumIndividualDigitsInString(factorialAsString));
}
public void Problem16()
{
string powerAsString = ((BigInteger)Math.Pow(2, 1000)).ToString();
Assert.Equal(1366, EulerHelperFunctions.SumIndividualDigitsInString(powerAsString));
}
