public void EvenValueReturnsHalf()
{
var startStep = new CollatzStep {
Value = 24, Step = 8
};
var expectedStep = new CollatzStep {
Value = 12, Step = 9
};
var actualStep = CollatzStepCalculator.Calculate(startStep);
Assert.Equal(expectedStep, actualStep);
}
public void OddValueReturnsTriplePlusOne()
{
var startStep = new CollatzStep {
Value = 35, Step = 0
};
var expectedStep = new CollatzStep {
Value = 106, Step = 1
};
var actualStep = CollatzStepCalculator.Calculate(startStep);
Assert.Equal(expectedStep, actualStep);
}
public static CollatzStep Calculate(CollatzStep input)
{
if (input.Value == 1)
{
return(input);
}
int nextStep = input.Step + 1;
int nextValue = (input.Value % 2 == 0) ? input.Value / 2 : (input.Value * 3) + 1;
return(new CollatzStep {
Value = nextValue, Step = nextStep
});
}