public static bool GetIsValidNextNumber(IList <BigInteger> previousNumbers, BigInteger nextNumber)
{
var pairSums = CombinationsHelper.CombinationsRosettaWoRecursion(previousNumbers.ToArray(), 2)
.Where(numberPair => numberPair[0] != numberPair[1])
.Select(numberPair => numberPair.Aggregate((item1, item2) => item1 + item2));
var result = pairSums.Contains(nextNumber);
return(result);
}
public static IList <long> GetAddressesWithMaskApplied(long decimalAddress, string mask)
{
var result = new List <long>();
var binaryValueBitArray = Convert.ToString(decimalAddress, 2).PadLeft(36, '0').ToCharArray();
for (int i = 0; i < 36; i++)
{
var maskBit = mask[i];
if ('0'.Equals(maskBit))
{
continue;
}
binaryValueBitArray[i] = maskBit;
}
var numberOfFloatingBits = binaryValueBitArray.Where(b => 'X'.Equals(b)).Count();
var floatingBitCombinations = CombinationsHelper.GetAllPossibleOutcomesOfNExperiments(new char[] { '0', '1' }, numberOfFloatingBits);
var floatingBitPositions = new List <int>();
for (int i = 0; i < 36; i++)
{
if ('X'.Equals(binaryValueBitArray[i]))
{
floatingBitPositions.Add(i);
}
}
var addressBitArrays = new List <char[]>();
foreach (var floatingBitComination in floatingBitCombinations)
{
var currentAddressBitArray = binaryValueBitArray.ToArray();
for (int i = 0; i < numberOfFloatingBits; i++)
{
var floatingBitPosition = floatingBitPositions[i];
currentAddressBitArray[floatingBitPosition] = floatingBitComination[i];
}
addressBitArrays.Add(currentAddressBitArray);
}
foreach (var addressBitArray in addressBitArrays)
{
var addressBinaryString = new string(addressBitArray);
var address = Convert.ToInt64(addressBinaryString, 2);
result.Add(address);
}
return(result);
}
public static IList <int> GetNumbersThatSumToTarget(IList <int> numberList, int numberOfEntries, int targetSum)
{
var combinationsEnumerator = CombinationsHelper.CombinationsRosettaWoRecursion(numberList.ToArray(), numberOfEntries);
foreach (var numberCombination in combinationsEnumerator)
{
var testSum = 0;
foreach (var currentNumber in numberCombination)
{
testSum += currentNumber;
if (testSum > targetSum)
{
break;
}
}
if (testSum == targetSum)
{
return(numberCombination.ToList());
}
}
return(new List <int>());
}
public IActionResult Combinations([FromQuery] int[] arr)
{
var result = CombinationsHelper.CombinationsRosettaWoRecursion(arr, 2);
return(Ok(result));
}
