find - Longest chain of letters in word JavaScript

Question

I need to write a program that is find longest chain of letters in a word and displays it in a console.log with their length. Example aaaAAAAdddeess - console.log( 'AAAA' ,4 ). Program must be in JavaScript and must distinguish capital letters. I`ve tried something like

const word = 'aaadddAAAwwwweee'

let newWord = ' '

for (let i = 0; i < word.length; i++) {

  if (word[i] === word[i + 1]) {

    newWord += word[i] + word[i + 1]

    i++

  }

}

console.log(newWord, newWord.lenght)

Answer 1

You can split the word to letters and check each letter with next one. Then push current sequence in an array, it will be current max sequence. Each iteration check the size of current longest sequnece with max sequence.

  const word = 'aaadddAAAwwwweee'

  let lettersArr = word.split('');
  let currentSequence = [];
  let maxSequence = [];

  for (let index = 0; index < lettersArr.length; index++) {
      let element = lettersArr[index];
      currentSequence = [element];

      for (let i = index + 1; i < lettersArr.length; i++) {
          if (lettersArr[index] == lettersArr[i]) {
              currentSequence.push(lettersArr[index]);
          } else {
              break;
          }
      }

      if (currentSequence.length > maxSequence.length) {
          maxSequence = currentSequence;
      }
  }

  let newWord = maxSequence.join('');

  console.log(newWord, newWord.length);