Contiguous Groups

contiguous-groups.js

const ContiguousGroups = (array) => {
  const arrayValues = array.sort();

  let contiguousCount = 0,
    foundMatch = false;

  arrayValues.map(function(item, index) {
    let findDifference = Math.abs(item - arrayValues[index + 1]);

    if (!isNaN(findDifference) && findDifference === 0) {
      contiguousCount++;
      foundMatch = true;
    }

    if (foundMatch === true && !isNaN(findDifference) && arrayValues[index + 1] !== 'undefined' && findDifference === 1) {
      contiguousCount++;
    }

  });

  return contiguousCount;
}

ContiguousGroups([5, 5, 1, 2, 6, 8, 9]);