| 4 | 4 | // |
| 5 | 5 | |
| 6 | 6 | export class Crypto { |
| 7 | | constructor() { |
| 8 | | throw new Error('Remove this line and implement the function'); |
| 7 | constructor(plaintext) { |
| 8 | this.plaintext = plaintext || ''; |
| 9 | } |
| 10 | |
| 11 | normalize() { |
| 12 | // Edge Case: empty input string |
| 13 | if (!this.plaintext) return ''; |
| 14 | |
| 15 | return this.plaintext.toLowerCase().replace(/[^a-z0-9]/g, ''); |
| 9 | 16 | } |
| 10 | 17 | |
| 11 | 18 | get ciphertext() { |
| 12 | | throw new Error('Remove this line and implement the function'); |
| 19 | const normalized = this.normalize(); |
| 20 | |
| 21 | // Edge Case: empty normalized string |
| 22 | if (!normalized) return ''; |
| 23 | |
| 24 | const length = normalized.length; |
| 25 | |
| 26 | // Calculate rectangle dimensions |
| 27 | // Find the smallest c such that r*c >= length, c >= r, and c - r <= 1 |
| 28 | let c = Math.ceil(Math.sqrt(length)); |
| 29 | let r = Math.ceil(length / c); |
| 30 | |
| 31 | // Adjust dimensions to meet constraints |
| 32 | while (r * c < length) { |
| 33 | c++; |
| 34 | r = Math.ceil(length / c); |
| 35 | } |
| 36 | |
| 37 | // Ensure c >= r and c - r <= 1 |
| 38 | while (c < r || c - r > 1) { |
| 39 | c++; |
| 40 | r = Math.ceil(length / c); |
| 41 | } |
| 42 | |
| 43 | // Create the rectangle |
| 44 | const rectangle = []; |
| 45 | for (let i = 0; i < r; i++) { |
| 46 | const start = i * c; |
| 47 | const end = start + c; |
| 48 | let row = normalized.slice(start, end); |
| 49 | |
| 50 | // Pad the row if necessary |
| 51 | while (row.length < c) { |
| 52 | row += ' '; |
| 53 | } |
| 54 | |
| 55 | rectangle.push(row); |
| 56 | } |
| 57 | |
| 58 | // Read down the columns |
| 59 | let result = ''; |
| 60 | for (let col = 0; col < c; col++) { |
| 61 | for (let row = 0; row < r; row++) { |
| 62 | result += rectangle[row][col]; |
| 63 | } |
| 64 | |
| 65 | // Add space between chunks except for the last one |
| 66 | if (col < c - 1) { |
| 67 | result += ' '; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | return result; |
| 13 | 72 | } |
| 14 | 73 | } |
| 74 | |
| 75 | // Handled Edge Cases: empty input string, empty normalized string |