export function groupAnagrams(words: string[]): string[][] {
  let result = []
  for(let i = 0; i < words.length; i++) {
    let current = words[i].split('').sort().join('')
    let group = []
    for(let j = 0; j < words.length; j++){
      if(current === words[j].split('').sort().join('')) group.push(words[j])
    }

    const exists = result.some(item => JSON.stringify(item) === JSON.stringify(group));
    if (!exists) result.push(group);  
  }
  return result.map((v) => v.sort()).sort();
}