Decipher The Seven Segments

Apr 25, 2018

View this challenge at r/dailyprogrammer

Challenge Description

Description

Today’s challenge will be to create a program to decipher a seven segment display, commonly seen on many older electronic devices.

Input Description

For this challenge, you will receive 3 lines of input, with each line being 27 characters long (representing 9 total numbers), with the digits spread across the 3 lines. Your job is to return the represented digits. You don’t need to account for odd spacing or missing segments.

Output Description

Your program should print the numbers contained in the display.

Challenge Inputs

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

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

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

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

Challenge Outputs

My Solution

JavaScript

var rl = require('readline').createInterface({
  input: process.stdin
})

const nums = { // 7 segment chars for each digit
  ' _ | ||_|': 0,
  '     |  |': 1,
  ' _  _||_ ': 2,
  ' _  _| _|': 3,
  '   |_|  |': 4,
  ' _ |_  _|': 5,
  ' _ |_ |_|': 6,
  ' _   |  |': 7,
  ' _ |_||_|': 8,
  ' _ |_| _|': 9
}

new Promise(resolve => { // make groups of 4 lines
  const lines = [[]]
  let count = 0
  rl.on('line', line => {
    lines[count].push(line)
    if(lines[count].length == 4){
      count++
      lines[count] = []
    }
  })
  rl.on('close', () => resolve(lines))
})
  .then(inputs => inputs
    .map(lines => lines.slice(0, 3)) // remove the empty line after each input
    .map(lines => lines
      .map(line => line.concat('                           ').slice(0, 27))) // make every line the same length
    .forEach(line => {
      let digits = [0,1,2,3,4,5,6,7,8].map(i => // get all chars for each digit
          line[0].slice(i * 3, i * 3 + 3).concat(
          line[1].slice(i * 3, i * 3 + 3)).concat(
          line[2].slice(i * 3, i * 3 + 3)))
        .map(chars => nums[chars]) // get the number for each digit
      console.log(digits.reduce((a, x) => a + x, '')) // output the number
    }))
  .catch(e => console.error(e))