public override AnswerMessage GetSolution(long first, long second)
{
if (Sen.Contains(second))
{
switch (second)
{
case 7:
{
var solution = $"{first} - {second} = {first} - {Ten} + 3 = ";
return(new AnswerMessage(AppResources.Minus7Message, solution));
}
case 8:
{
var solution = $"{first} - {second} = {first} - {Ten} + 2 = ";
return(new AnswerMessage(AppResources.Minus8Message, solution));
}
case 9:
{
var solution = $"{first} - {second} = {first} - {Ten} + 1 = ";
return(new AnswerMessage(AppResources.Minus9Message, solution));
}
default: return(null);
}
}
if (second > 10)
{
return(GetMultiDigitSolution(first, second));
}
return(null);
}
public override AnswerMessage GetSolution(long first, long second)
{
if (first + second <= Ten)
{
return(null);
}
if (Sen.Contains(first) && (first + second) % 10 != 0)
{
switch (first)
{
case 7:
{
var solution = $"{first} + {second} = {Ten} + {second} - 3 = ";
return(new AnswerMessage(AppResources.Plus_7_8_9_Message, solution));
}
case 8:
{
var solution = $"{first} + {second} = {Ten} + {second} - 2 = ";
return(new AnswerMessage(AppResources.Plus_7_8_9_Message, solution));
}
case 9:
{
var solution = $"{first} + {second} = {Ten} + {second} - 1 = ";
return(new AnswerMessage(AppResources.Plus_7_8_9_Message, solution));
}
default: return(null);
}
}
if (Sen.Contains(second) && (first + second) % 10 != 0)
{
switch (second)
{
case 7:
{
var solution = $"{first} + {second} = {first} + {Ten} - 3 = ";
return(new AnswerMessage(AppResources.Plus_7_8_9_Message, solution));
}
case 8:
{
var solution = $"{first} + {second} = {first} + {Ten} - 2 = ";
return(new AnswerMessage(AppResources.Plus_7_8_9_Message, solution));
}
case 9:
{
var solution = $"{first} + {second} = {first} + {Ten} - 1 = ";
return(new AnswerMessage(AppResources.Plus_7_8_9_Message, solution));
}
default: return(null);
}
}
if (first + second > 10 && second < 10)
{
var answer = first + second;
var withTransition = first / 10 < answer / 10;
if (answer > 10 && withTransition && answer % 10 != 0)
{
var x = answer / 10 * 10;
var secondOne = x - first;
var secondTwo = answer - x;
var solution = $"{first} + {second} = {first} + {secondOne} + {secondTwo} = ";
return(new AnswerMessage(AppResources.Addition1To20Rule, solution));
}
return(null);
}
if (first > 10 && second > 10)
{
return(GetMultiDigitSolution(first, second));
}
return(null);
}