0 is not a prime number.

Not a kata issue. Closing.

Tax is a rate you must pay as a percentage of your earnings. Your invested savings themselves are not included in the tax calculation, only the earnings made from the interest. If, in a given year, you earn $100, a tax rate of 20% (0.2) would mean $20 must be paid as tax. Your invested savings would increase by $80 that year.

That's too big; remember that you have to return to your starting point.

OP solved it, closing

Thanks for your code.

If you want to see the test cases, you can do that after finishing or forfeiting the kata. :-)

I tried out your code and I couldn't recreated the problems with the test cases.

That being said, your code does not completely solve the task. As a hint, try merging "ab" and "bc" to "abcb". It should work.

(Also, as a side note, if you want to use Java in a bigger context, the convention is that local variables start with a lower-case letter, e.g. mergeWord. It doesn't make any technical difference, so if you're just doing it for fun, you can disregard this. :-) )

The test is ok, your code is not. The expected result is ok, there are 3 repeated letters, a, b and c, it doesn't matter how many times each letter is repeated.

No, you changed the method name. It should be 'squareDigits', not 'squareDigit'. The issue comes from your code, not kata itself.

You do not ned to import JUnit if you have problems with it. You can just add main and call Prime.isPrime(4) from it.

And what happens when you step through your code with debugger locally in your IDE?

Also character arrays are zero indexed.

Because not all walks are of 10 length. Not a kata issue!

It should be at least 11 * 11.

It doesn't matter. Think of it as an infinite grid if you need it.