##Problem definition:

Once upon a time in a strange situation, people called a number ugly if it was divisible by any of the one-digit primes (\$2\$, \$3\$, \$5\$ or \$7\$). Thus, \$14\$ is ugly, but \$13\$ is fine. \$39\$ is ugly, but \$121\$ is not. Note that \$0\$ is ugly. Also note that negative numbers can also be ugly: \$-14\$ and \$-39\$ are examples of such numbers.

##Input Sample:

##Output Sample:

Is the code understandable? How can it be improved? Here's the challenge.

Here's the challenge:

Once upon a time in a strange situation, people called a number ugly if it was divisible by any of the one-digit primes (\$2\$, \$3\$, \$5\$ or \$7\$). Thus, \$14\$ is ugly, but \$13\$ is fine. \$39\$ is ugly, but \$121\$ is not. Note that \$0\$ is ugly. Also note that negative numbers can also be ugly: \$-14\$ and \$-39\$ are examples of such numbers.

Input Sample:

Output Sample:

Is the code understandable? How can it be improved?

Here is an example of challenge I try to solve.

Is this understandable? How can the code be improved?

##Problem definition:

Once upon a time in a strange situation, people called a number ugly if it was divisible by any of the one-digit primes (\$2\$, \$3\$, \$5\$ or \$7\$). Thus, \$14\$ is ugly, but \$13\$ is fine. \$39\$ is ugly, but \$121\$ is not. Note that \$0\$ is ugly. Also note that negative numbers can also be ugly: \$-14\$ and \$-39\$ are examples of such numbers.

One day on your free time, you are gazing at a string of digits, something like:

123456

You are amused by how many possibilities there are if you are allowed to insert plus or minus signs between the digits. For example you can make:

1 + 234 - 5 + 6 = 236

which is ugly. Or:

123 + 4 - 56 = 71

which is not ugly.

It is easy to count the number of different ways you can play with the digits: Between each two adjacent digits you may choose put a plus sign, a minus sign, or nothing. Therefore, if you start with N digits there are \$3^{N-1}\$ expressions you can make. Note that it is fine to have leading zeros for a number. If the string is '01023', then '01023', '0+1-02+3' and '01-023' are legal expressions.

Your task is simple: Among the \$3^{N-1}\$ expressions, count how many of them evaluate to an ugly number.

##Input Sample:

Your program should accept as its first argument a path to a filename. Each line in this file is one test case. Each test case will be a single line containing a non-empty string of decimal digits. The string in each test case will be non-empty and will contain only characters '\$0\$' through '\$9\$'. Each string is no more than 13 characters long. E.g.

1
9
011
12345

##Output Sample:

Print out the number of expressions that evaluate to an ugly number for each test case, each one on a new line. E.g.

0
1
6
64

Is the code understandable? How can it be improved? Here's the challenge.

I'm learning C++ programming and I do like to solve any types of challenges/exercises, and since I have huge desire to become better I decided to post some of my solved challenges here, so that I can find out how my coding style is.

Is it understandable, how can the code be improved? And anything you think that may be helpful. Here is an example of challenge I try to solve.

Here is an example of challenge I try to solve.

Is this understandable? How can the code be improved?