Problem8.js

// The four adjacent digits in the 1000-digit number that have the greatest product are 9 × 9 × 8 × 9 = 5832.
// Find the thirteen adjacent digits in the 1000-digit number that have the greatest product. What is the value of this product?

var num = ("731671765313306249192251196744265747423553491949349698352031277450632623957831801698480186947885183858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450")

num = num.split('')
function adjProd(x) {
  lar = 0;
  numb = 1;
  place = 0;
  while (place <= num.length-x) {
    for (var i = place; i < place + x; i++) {
      numb *= num[i];
    }
    if (numb>lar) {
      lar = numb;
    }
    numb = 1;
    place ++;
  }
  return lar;
}

console.log(adjProd(4))