public void Tests()
{
var num = new StringInteger("098");
Assert.Equal("98", num.ToString());
num.Increment();
Assert.Equal("99", num.ToString());
Assert.Equal(2, num.GetNonZeroNumbers());
num.Increment();
Assert.Equal("100", num.ToString());
Assert.Equal(1, num.GetNonZeroNumbers());
Assert.True(String.Compare(num.ToString(), "101") < 0);
Assert.True(String.Compare(num.ToString(), "099") > 0);
}
public static int getNumberOfIntegers(string L, string R, int K)
{
var result = 0;
var l = new StringInteger(L);
l.Increment();
do
{
if (l.GetNonZeroNumbers() == K)
{
result++;
}
l.Increment();
} while (String.Compare(l.ToString().PadLeft(R.Length, '0'), R) <= 0);
return(result % 1000000007);
}