Practice Javascript - Text Practice - 10FastFingers.com

Text Practice Mode

Practice Javascript

created Wednesday June 25, 16:10 by Michael Lopes

0

Rating

773 words

6 completed

00:00

const SEPARATOR = '$';
function buildZArray(zString) {
  const zArray = new Array(zString.length).fill(null).map(() => 0);

  let zBoxLeftIndex = 0;
  let zBoxRightIndex = 0;

  let zBoxShift = 0;

  for (let charIndex = 1; charIndex < zString.length; charIndex += 1) {
    if (charIndex > zBoxRightIndex) {
      zBoxLeftIndex = charIndex;
      zBoxRightIndex = charIndex;

      while (
        zBoxRightIndex < zString.length
        && zString[zBoxRightIndex - zBoxLeftIndex] === zString[zBoxRightIndex]
      ) {
        zBoxRightIndex += 1;
      }
      zArray[charIndex] = zBoxRightIndex - zBoxLeftIndex;

      zBoxRightIndex -= 1;
    } else {

      zBoxShift = charIndex - zBoxLeftIndex;

      if (zArray[zBoxShift] < (zBoxRightIndex - charIndex) + 1) {
        zArray[charIndex] = zArray[zBoxShift];
      } else {
        zBoxLeftIndex = charIndex;

        while (
          zBoxRightIndex < zString.length
          && zString[zBoxRightIndex - zBoxLeftIndex] === zString[zBoxRightIndex]
        ) {
          zBoxRightIndex += 1;
        }

        zArray[charIndex] = zBoxRightIndex - zBoxLeftIndex;

        zBoxRightIndex -= 1;
      }
    }
  }

  return zArray;
}
export default function zAlgorithm(text, word) {

  const wordPositions = [];

  const zString = `${word}${SEPARATOR}${text}`;

  const zArray = buildZArray(zString);

  for (let charIndex = 1; charIndex < zArray.length; charIndex += 1) {
    if (zArray[charIndex] === word.length) {
      const wordPosition = charIndex - word.length - SEPARATOR.length;
      wordPositions.push(wordPosition);
    }
  }

  return wordPositions;
}

saving score / loading statistics ...