public int DigitSumEqual(int upperLimit, Func <int, int> digitMap)
{
var digitMapLookup = new KeyValueMap <int, int>(digitMap);
Func <IEnumerable <int>, int> digitSum = xs => xs.Select(digitMapLookup.GetValue).Sum();
return(Enumerable.Range(10, upperLimit)
.Select(x => new { Num = x, ListNum = BigNumberHelper.GetAsListRepresentingNumber(x) })
.Where(x => x.Num == digitSum(x.ListNum))
.Sum(x => x.Num));
}
public void Problem97()
{
var q = Enumerable.Repeat(2, 7830457);
var rt = q.Aggregate(Enumerable.Repeat <int>(1, 1).ToList(), (x, y) => BigNumberHelper.MultiplyListRepresentingNumber(x, y, 10));
//MultiplyListRepresentingNumberVoid(rt, 28433);
var d = BigNumberHelper.GetAsListRepresentingNumber(28433);
var s = BigNumberHelper.MultiplyListRepresentingNumber(rt, d);
}
public int Problem25()
{
List <int> result = new List <int>();
List <int> prevprev = BigNumberHelper.GetAsListRepresentingNumber(1);
List <int> prev = BigNumberHelper.GetAsListRepresentingNumber(1);
int n = 2;
while (result.Count() < 1000)
{
result = BigNumberHelper.AddListRepresentingNumbers(prevprev, prev);
prevprev = prev;
prev = result;
n++;
}
return(n);
}
public int Problem20()
{
int i = 100;
List <int> num = BigNumberHelper.GetAsListRepresentingNumber(i);
while (i > 1)
{
List <int> num2 = BigNumberHelper.GetAsListRepresentingNumber(i - 1);
num = BigNumberHelper.MultiplyListRepresentingNumber(num, num2);
i--;
}
int answer = num.Sum();
return(answer);
}