| 8 | 8 | * @returns {string} |
| 9 | 9 | */ |
| 10 | 10 | export const convert = (text) => { |
| 11 | | throw new Error('Remove this line and implement the function'); |
| 11 | // Edge Case: Empty input |
| 12 | if (!text) return ''; |
| 13 | |
| 14 | const lines = text.split('\n'); |
| 15 | |
| 16 | // Edge Case: Invalid number of lines (must be multiple of 4) |
| 17 | if (lines.length % 4 !== 0) { |
| 18 | throw new Error('Invalid input grid'); |
| 19 | } |
| 20 | |
| 21 | const result = []; |
| 22 | |
| 23 | // Process 4 lines at a time (one digit row) |
| 24 | for (let i = 0; i < lines.length; i += 4) { |
| 25 | const line1 = lines[i]; |
| 26 | const line2 = lines[i + 1]; |
| 27 | const line3 = lines[i + 2]; |
| 28 | const line4 = lines[i + 3]; |
| 29 | |
| 30 | // Edge Case: Fourth line is not blank (allow trailing spaces) |
| 31 | if (line4.trim() !== '') { |
| 32 | throw new Error('Invalid input grid'); |
| 33 | } |
| 34 | |
| 35 | // Edge Case: Lines have different lengths (except fourth line which can be blank with spaces) |
| 36 | let lineWidth = line1.length; |
| 37 | |
| 38 | // Allow some flexibility in line lengths for multi-line inputs |
| 39 | // but ensure they are reasonable for OCR processing |
| 40 | if (line2.length !== lineWidth || line3.length !== lineWidth) { |
| 41 | // Check if the difference is small and could be due to formatting |
| 42 | const maxLen = Math.max(lineWidth, line2.length, line3.length); |
| 43 | const minLen = Math.min(lineWidth, line2.length, line3.length); |
| 44 | |
| 45 | // If the difference is more than 3 characters, it's likely invalid |
| 46 | if (maxLen - minLen > 3) { |
| 47 | throw new Error('Invalid input grid'); |
| 48 | } |
| 49 | |
| 50 | // Use the maximum length for processing |
| 51 | lineWidth = maxLen; |
| 52 | } |
| 53 | |
| 54 | // Edge Case: Line length is not a multiple of 3 |
| 55 | if (lineWidth % 3 !== 0) { |
| 56 | throw new Error('Invalid input grid'); |
| 57 | } |
| 58 | |
| 59 | let rowResult = ''; |
| 60 | |
| 61 | // Process each 3-character wide digit |
| 62 | for (let j = 0; j < lineWidth; j += 3) { |
| 63 | const digitPattern = [ |
| 64 | line1.substring(j, j + 3), |
| 65 | line2.substring(j, j + 3), |
| 66 | line3.substring(j, j + 3) |
| 67 | ]; |
| 68 | |
| 69 | rowResult += recognizeDigit(digitPattern); |
| 70 | } |
| 71 | |
| 72 | result.push(rowResult); |
| 73 | } |
| 74 | |
| 75 | return result.join(','); |
| 76 | }; |
| 77 | |
| 78 | const recognizeDigit = (pattern) => { |
| 79 | const patterns = { |
| 80 | ' _ | ||_|': '0', |
| 81 | ' | |': '1', |
| 82 | ' _ _||_ ': '2', |
| 83 | ' _ _| _|': '3', |
| 84 | ' |_| |': '4', |
| 85 | ' _ |_ _|': '5', |
| 86 | ' _ |_ |_|': '6', |
| 87 | ' _ | |': '7', |
| 88 | ' _ |_||_|': '8', |
| 89 | ' _ |_| _|': '9' |
| 90 | }; |
| 91 | |
| 92 | const key = pattern.join(''); |
| 93 | |
| 94 | // Edge Case: Unrecognized pattern |
| 95 | return patterns[key] || '?'; |
| 12 | 96 | }; |
| 97 | |
| 98 | // Handled Edge Cases: Empty input, Invalid number of lines, Fourth line is not blank, Lines have different lengths, Line length is not a multiple of 3, Unrecognized pattern |