export function decodeMessage(encoded: string, k: number): string {
  const n = encoded.length
  const rows = Math.ceil(n / k);
  const grid = Array.from({length: rows}, () => Array(k).fill(' '))
  
  let i = 0

  for(let col = 0; col < k; col++){
    for(let row = 0; row < rows; row++){
      const rowMajorIndex = row * k + col
      if (rowMajorIndex < n) {
        grid[row][col] = encoded[i++];
      }
    }
  }
  

  return grid.map((row) => row.join("")).join("").trimEnd();
}