Problem 35 incorrect answer

Stephen, Hi! Thanks for your message!

I think this little discrepancy is because your solution does not perform this operation:

>At the end of each year ... rounded down to whole cents (as in example above).

As we see it only becomes important when the term is long and percents are small...

I have a question about this same problem. My solution sometimes gives the right answers and sometimes makes a mistake of one year. Should I be concerned and try to make it better or could it be just an error of rounding or something?

P.S. The errors happen very rarelly.

Hi,

Does your code round down to whole cents? This bit looks like it may round up

if ((int)temp%10 >= 5) {
    temp += 10;
}

Oh wow. As English is not my main language I wouldn't have noticed the word down. I fixed my code, Thank You.

Hi! I got the corrected solution. however, when I run the example, the last two lines are 29 9316.79 30 10062.13 while your answer is 29 9316.82 30 10062.16 the other are same.

Then I find the problem(int(5033.61 * 100) = 503360), how I solve the problem?

Sorry, I can't help you with python, but if

int(5033.61 * 100) = 503360

What is

5033.61 * 100

From the Python2 documentation:

int(x=0): 

Return an integer object constructed from a number or string x, or return 0 if no arguments are given. If x is a number, it can be a plain integer, a long integer, or a floating point number. If x is floating point, the conversion truncates towards zero. If the argument is outside the integer range, the function returns a long object instead.

int(x, base=10): 

If x is not a number or if base is given, then x must be a string or Unicode object representing an integer literal in radix base. Optionally, the literal can be preceded by + or - (with no space in between) and surrounded by whitespace. A base-n literal consists of the digits 0 to n-1, with a to z (or A to Z) having values 10 to 35. The default base is 10. The allowed values are 0 and 2-36. Base-2, -8, and -16 literals can be optionally prefixed with 0b/0B, 0o/0O/0, or 0x/0X, as with integer literals in code. Base 0 means to interpret the string exactly as an integer literal, so that the actual base is 2, 8, 10, or 16.

Now, as for the question of whether int(5033.61 * 100) = 503360, Python 2.7.2 does not agree with this assertion. In fact, it creates an integer object of value 503361.

Furthermore, 5033.61 * 100 returns a value of 503361.00000000006. (Why is this happening?)

So, to summarize, for all Python versions (through 2.7.11 and 3.5):

• If you want an integral value, and precision/rounding rules aren't important to you, or just want naive truncation, or are trying to get an integer out of a non-base 10 value or have an object which represents an integer but isn't an int ... go ahead and use the int() constructor to truncate.
• If you want a non-integral value, and precision/rounding rules aren't important to you, but you want to control the number of decimal places in the actual value, use the round() built-in functions.
• If you want a non-integral value, and precision/rounding rules are very important (see the #6: Rounding task), use the decimal module, which has a Decimal.quantize() method.