export const addRoundKey = (state: number[][], roundKey: number[][]): number[][] => {
  const result: number[][] = [
    [0, 0, 0, 0],
    [0, 0, 0, 0],
    [0, 0, 0, 0],
    [0, 0, 0, 0]
  ]

  for (let row = 0;row < 4;row++) {
    for (let col = 0;col < 4;col++) {
      result[row][col] = state[row][col] ^ roundKey[row][col]
    }
  }

  return result
}