From 426208d3beffb96d961b04ac6bede15ef679f823 Mon Sep 17 00:00:00 2001 From: newt! Date: Fri, 29 Oct 2021 02:16:14 +0100 Subject: [PATCH] (euler) - #8 --- euler/src/8 - Largest Product in a Series.ts | 36 ++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 euler/src/8 - Largest Product in a Series.ts diff --git a/euler/src/8 - Largest Product in a Series.ts b/euler/src/8 - Largest Product in a Series.ts new file mode 100644 index 0000000..bf89397 --- /dev/null +++ b/euler/src/8 - Largest Product in a Series.ts @@ -0,0 +1,36 @@ +const largestProduct = (number: bigint | number, adjacentDigits: number) => { + let cursorIndex = 0; + const selections: number[][] = []; + + while (cursorIndex < number.toString().length) { + const characters = number.toString().split(''); + + // Select the next 13 numbers + const selection: number[] = []; + + for (let i = 0; i < adjacentDigits; i++) { + selection.push(parseInt(characters[cursorIndex + i])); + } + + if (!selection.includes(NaN)) selections.push(selection); + + // Keep moving the cursor along + cursorIndex++; + } + + // Work out the products + const products: number[] = []; + + for (let i = 0; i < selections.length; i++) { + products.push(selections[i].reduce((a, b) => a * b)); + } + + // Return the largest product + return products.sort((a, b) => b - a)[0]; +}; + +const number = BigInt( + '7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450' +); + +console.log(largestProduct(number, 13));