dev.to staff

Posted on Apr 9, 2020

Daily Challenge #222 - Parse Bank Account Numbers

#challenge

You work for a bank, which has recently purchased an ingenious machine to assist in reading letters and faxes sent in by branch offices.

The machine scans the paper documents, and produces a string with a bank account that looks like this:

    _  _     _  _  _  _  _
  | _| _||_||_ |_   ||_||_|
  ||_  _|  | _||_|  ||_| _|

... why did we buy this machine?

Anyway, your task is to write a function that can take bank account string and parse it into actual account numbers.

Example

 _  _  _  _  _  _  _  _  _ 
| | _| _|| ||_ |_   ||_||_|     => 23056789
|_||_  _||_| _||_|  ||_| _|

Tests

 _  _  _  _  _  _  _  _  _ 
|_| _| _||_||_ |_ |_||_||_| 
|_||_  _||_| _||_| _||_| _|

  _  _     _  _  _  _  _
| _| _||_||_ |_   ||_||_|
||_  _|  | _||_|  ||_| _|

Good luck!

This challenge comes from arhigod on CodeWars. Thank you to CodeWars, who has licensed redistribution of this challenge under the 2-Clause BSD License!

Want to propose a challenge idea for a future post? Email yo+challenge@dev.to with your suggestions!

Top comments (3)

Mihail Malo • Apr 9 '20 • Edited

Rust. Who needs error checking when you can support multiline instead?

use itertools::{izip, Itertools}; // 0.9.0
fn smol(big: &str) -> String {
    big.lines()
        .tuples()
        .flat_map(|(l1, l2, l3)| {
            izip!(l1.chars(), l2.chars(), l3.chars())
                .tuples()
                .map(|digit| match digit {
                    ((' ', ' ', ' '), (' ', ' ', ' '), (' ', '|', '|')) => '1',
                    ((' ', ' ', '|'), ('_', '_', '_'), (' ', '|', ' ')) => '2',
                    ((' ', ' ', ' '), ('_', '_', '_'), (' ', '|', '|')) => '3',
                    ((' ', '|', ' '), (' ', '_', ' '), (' ', '|', '|')) => '4',
                    ((' ', '|', ' '), ('_', '_', '_'), (' ', ' ', '|')) => '5',
                    ((' ', '|', '|'), ('_', '_', '_'), (' ', ' ', '|')) => '6',
                    ((' ', ' ', ' '), ('_', ' ', ' '), (' ', '|', '|')) => '7',
                    ((' ', '|', '|'), ('_', '_', '_'), (' ', '|', '|')) => '8',
                    ((' ', '|', ' '), ('_', '_', '_'), (' ', '|', '|')) => '9',
                    x => unreachable!(),
                })
        })
        .collect()
}

fn main() {
    println!(
        "{}",
        smol(
            r"    _  _     _  _  _  _  _ 
  | _| _||_||_ |_   ||_||_|
  ||_  _|  | _||_|  ||_| _|
    _  _     _  _  _  _  _ 
  | _| _||_||_ |_   ||_||_|
  ||_  _|  | _||_|  ||_| _|
    _  _     _  _  _  _  _ 
  | _| _||_||_ |_   ||_||_|
  ||_  _|  | _||_|  ||_| _|"
        )
    );
}

Look at it go

Vidit Sarkar • Apr 9 '20 • Edited

Python solution

# stores the modified string representation of a digit
digitStringDict = {
    " _ | ||_|" : "0",
    "     |  |" : "1",
    " _  _||_ " : "2",
    " _  _| _|" : "3",
    "   |_|  |" : "4",
    " _ |_  _|" : "5",
    " _ |_ |_|" : "6",
    " _   |  |" : "7",
    " _ |_||_|" : "8",
    " _ |_| _|" : "9"
}

# takes a multiline string as input
# outputs the int representation of that
def stringToAccountNumber(account: str) -> int:
    account = account.strip("\n")
    parts = account.split("\n") # split the actual string into three strings based on new-line character
    numberStr = "" # stores the string representation of the number

    for i in range(0,len(parts[0]),3):
        numberStr += digitStringDict[parts[0][i:i+3]+parts[1][i:i+3]+parts[2][i:i+3]]

    return int(numberStr)

Output,

test1 = '''
 _  _  _  _  _  _  _  _  _ 
|_| _| _||_||_ |_ |_||_||_|
|_||_  _||_| _||_| _||_| _|

'''

test2 = '''
    _  _     _  _  _  _  _ 
  | _| _||_||_ |_   ||_||_|
  ||_  _|  | _||_|  ||_| _|

'''

test3 = '''
 _  _  _  _  _  _  _  _  _ 
| | _| _|| ||_ |_   ||_||_|
|_||_  _||_| _||_|  ||_| _|

'''

print(stringToAccountNumber(test1)) # output -> 823856989
print(stringToAccountNumber(test2)) # output -> 123456789
print(stringToAccountNumber(test3)) # output -> 23056789

Dan Keefe • Apr 9 '20 • Edited

This is a rather hacky Python solution that relies on a dictionary of strings mapping to digits. I made the assumption that input would come as an array of strings, one for each level of the digits.

Code

digit_dict = {" _ | | _ ": 0, "     |  |": 1,
              " _  _||_ ": 2, " _  _| _|": 3,
              "   |_|  |": 4, " _ |_  _|": 5,
              " _ |_ |_|": 6, " _   |  |": 7,
              " _ |_||_|": 8, " _ |_| _|" : 9}

def parse_bank_code(str_list, digit_dict):
  """
  Function that takes awkward digit string and and digit dict;
  returns a normal string of digits.
  """

  digits = []  # Holder for digits

  # Loop through three places at a time
  for i in range(0, len(str_list[0]), 3):

    # Take three characters from each level as a list
    digit = [x[i:i+3] for x in str_list]

    # Join the characters together and get the dict value
    digit = digit_dict["".join(digit)]

    # Add the digit as a string to the list
    digits.append(str(digit))

  # Return the final code
  return "".join(digits)

DEV Community

Daily Challenge #222 - Parse Bank Account Numbers

Top comments (3)

Code

Read next

Gravando em um arquivo

How White Screens Help Debug Color Calibration

Gerando entradas em um arquivo

How to insert elments using Javascript