Merge pull request #90 from cesarbess/swift-003/008

Feat: Adds Swift 003 008

src/003/p003.swift

@@ -0,0 +1,21 @@
+import Foundation
+
+extension Int {
+    func factors() -> [Int] {
+        let limit = Int(sqrt(Double(self)))
+        return (2...limit).filter { self % $0 == 0 }
+    }
+
+    func isPrime() -> Bool {
+        return self > 1 && !(2..<self).contains { self % $0 == 0 }
+    }
+}
+
+func solve() -> Int {
+    return 600851475143.factors()
+                        .filter { i in i.isPrime() }
+                        .max()!
+}
+
+let result = solve()
+print(result)

src/008/p008.swift

@@ -0,0 +1,40 @@
+let input =
+"""
+73167176531330624919225119674426574742355349194934
+96983520312774506326239578318016984801869478851843
+85861560789112949495459501737958331952853208805511
+12540698747158523863050715693290963295227443043557
+66896648950445244523161731856403098711121722383113
+62229893423380308135336276614282806444486645238749
+30358907296290491560440772390713810515859307960866
+70172427121883998797908792274921901699720888093776
+65727333001053367881220235421809751254540594752243
+52584907711670556013604839586446706324415722155397
+53697817977846174064955149290862569321978468622482
+83972241375657056057490261407972968652414535100474
+82166370484403199890008895243450658541227588666881
+16427171479924442928230863465674813919123162824586
+17866458359124566529476545682848912883142607690042
+24219022671055626321111109370544217506941658960408
+07198403850962455444362981230987879927244284909188
+84580156166097919133875499200524063689912560717606
+05886116467109405077541002256983155200055935729725
+71636269561882670428252483600823257530420752963450
+"""
+
+extension Collection {
+    func eachConsecutive(_ size: Int) -> Array<SubSequence> {
+        let droppedIndices = indices.dropFirst(size - 1)
+        return zip(indices, droppedIndices).map { return self[$0...$1] }
+    }
+}
+
+func solve() -> Int {
+    return input.flatMap { Int(String($0)) }
+                .eachConsecutive(13)
+                .map { $0.reduce(1, *) }
+                .max()!
+}
+
+let result = solve()
+print(result)