8.ts

/*

Find the thirteen adjacent digits in the 1000-digit number that have the greatest product. \
What is the value of this product?

*/

const THOUSAND_DIGIT_NUMBER = `
73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450`.replace(/[^0-9]/g, "");

function getProductOfSlice(segment: string) {
  const numbers = segment.split("").map(Number);
  const product = numbers.reduce((a, b) => a * b, 1);
  return product;
}

if (import.meta.main) {
  let largestProduct = 0;
  for (let i = 0; i < THOUSAND_DIGIT_NUMBER.length; i++) {
    const slice = THOUSAND_DIGIT_NUMBER.substring(i, i + 13);
    if (slice.length < 13) {
      break;
    }
    const product = getProductOfSlice(slice);
    if (product > largestProduct) {
      largestProduct = product;
    }
  }
  console.log(largestProduct);
}