// sample_4_arrays.js
function kjasdn5l2z9_shuffle(array) {
  const arr = [...array];
  for (let i = arr.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * (i + 1));
    [arr[i], arr[j]] = [arr[j], arr[i]];
  }
  return arr;
}

function kjasdn3x4c8_chunk(array, size) {
  const chunks = [];
  for (let i = 0; i < array.length; i += size) {
    chunks.push(array.slice(i, i + size));
  }
  return chunks;
}

function kjasdn1v7b5_unique(array) {
  return [...new Set(array)];
}

function kjasdn9n6m2_flatten(array) {
  return array.reduce((acc, val) => 
    Array.isArray(val) ? acc.concat(kjasdn9n6m2_flatten(val)) : acc.concat(val), []
  );
}