✨ Recursive solutions to AddTwoNumbers

Sources/Solutions/002 - Add Two Numbers/AddTwoNumbersRecursiveHelperSolution.swift

@@ -0,0 +1,32 @@
+//
+//  AddTwoNumbersRecursiveHelperSolution.swift
+//  LeetSwift
+//
+//  Created by Jobert Sá on 04/07/2024.
+//
+
+import Core
+import Foundation
+import Problems
+
+final class AddTwoNumbersRecursiveHelperSolution: AddTwoNumbersDefinition {
+
+    func addTwoNumbers(_ l1: ListNode?, _ l2: ListNode?) -> ListNode? {
+        addTwoNumbers(l1, l2, 0)
+    }
+
+    private func addTwoNumbers(
+        _ l1: ListNode?,
+        _ l2: ListNode?,
+        _ carry: Int
+    ) -> ListNode? {
+
+        guard l1 != nil || l2 != nil || carry > 0 else { return nil }
+
+        let sum = (l1?.val ?? 0) + (l2?.val ?? 0) + carry
+        let resultNode = ListNode(sum % 10)
+        resultNode.next = addTwoNumbers(l1?.next, l2?.next, sum / 10)
+
+        return resultNode
+    }
+}

Sources/Solutions/002 - Add Two Numbers/AddTwoNumbersRecursiveSolution.swift

@@ -0,0 +1,29 @@
+//
+//  AddTwoNumbersRecursiveSolution.swift
+//  LeetSwift
+//
+//  Created by Jobert Sá on 04/07/2024.
+//
+
+import Core
+import Foundation
+import Problems
+
+final class AddTwoNumbersRecursiveSolution: AddTwoNumbersDefinition {
+
+    func addTwoNumbers(_ l1: ListNode?, _ l2: ListNode?) -> ListNode? {
+        guard let l1 else { return l2 }
+        guard let l2 else { return l1 }
+
+        let sum = l1.val + l2.val
+        let resultNode = ListNode(sum % 10)
+        let nextNode = addTwoNumbers(l1.next, l2.next)
+        if sum > 9 {
+            resultNode.next = addTwoNumbers(nextNode, ListNode(1))
+        } else {
+            resultNode.next = nextNode
+        }
+
+        return resultNode
+    }
+}

Tests/SolutionsTests/002 - Add Two Numbers/AddTwoNumbersIterativeSolutionTests.swift

@@ -6,7 +6,6 @@
 //
 
 import XCTest
-@testable import Core
 @testable import Problems
 @testable import Solutions
 @testable import TestSupport
@@ -26,25 +25,4 @@ final class AddTwoNumbersIterativeSolutionTests: XCTestCase {
     }
 }
 
-extension AddTwoNumbersIterativeSolutionTests: TestCaseProviding {
-
-    func validateInput(_ input: (l1: ListNode?, l2: ListNode?)) -> Bool {
-        // TODO: Implement validation
-        true
-    }
-
-    var data: [TestData<(l1: ListNode?, l2: ListNode?), ListNode?>] { [
-        TestData(
-            input: ([2, 4, 3].listNode, [5, 6, 4].listNode),
-            expectedOutput: [7, 0, 8].listNode
-        ),
-        TestData(
-            input: ([0].listNode, [0].listNode),
-            expectedOutput: [0].listNode
-        ),
-        TestData(
-            input: ([9, 9, 9, 9, 9, 9, 9].listNode, [9, 9, 9, 9].listNode),
-            expectedOutput: [8, 9, 9, 9, 0, 0, 0, 1].listNode
-        )
-    ] }
-}
+extension AddTwoNumbersIterativeSolutionTests: AddTwoNumbersTestCaseProvider { }

Tests/SolutionsTests/002 - Add Two Numbers/AddTwoNumbersRecursiveHelperSolutionTests.swift

@@ -0,0 +1,28 @@
+//
+//  AddTwoNumbersRecursiveHelperSolutionTests.swift
+//  LeetSwift
+//
+//  Created by Jobert Sá on 04/07/2024.
+//
+
+import XCTest
+@testable import Problems
+@testable import Solutions
+@testable import TestSupport
+
+final class AddTwoNumbersRecursiveHelperSolutionTests: XCTestCase {
+
+    let solution: AddTwoNumbersDefinition = AddTwoNumbersRecursiveHelperSolution()
+
+    func testSolution() {
+        for testData in data {
+            let input = testData.input
+
+            let output = solution.addTwoNumbers(input.l1, input.l2)
+
+            XCTAssertEqual(output, testData.expectedOutput)
+        }
+    }
+}
+
+extension AddTwoNumbersRecursiveHelperSolutionTests: AddTwoNumbersTestCaseProvider { }

Tests/SolutionsTests/002 - Add Two Numbers/AddTwoNumbersRecursiveSolutionTests.swift

@@ -0,0 +1,28 @@
+//
+//  AddTwoNumbersRecursiveSolutionTests.swift
+//  LeetSwift
+//
+//  Created by Jobert Sá on 04/07/2024.
+//
+
+import XCTest
+@testable import Problems
+@testable import Solutions
+@testable import TestSupport
+
+final class AddTwoNumbersRecursiveSolutionTests: XCTestCase {
+
+    let solution: AddTwoNumbersDefinition = AddTwoNumbersRecursiveSolution()
+
+    func testSolution() {
+        for testData in data {
+            let input = testData.input
+
+            let output = solution.addTwoNumbers(input.l1, input.l2)
+
+            XCTAssertEqual(output, testData.expectedOutput)
+        }
+    }
+}
+
+extension AddTwoNumbersRecursiveSolutionTests: AddTwoNumbersTestCaseProvider { }

Tests/SolutionsTests/002 - Add Two Numbers/AddTwoNumbersTestCaseProvider.swift

@@ -0,0 +1,34 @@
+//
+//  AddTwoNumbersTestCaseProvider.swift
+//  LeetSwift
+//
+//  Created by Jobert Sá on 04/07/2024.
+//
+
+@testable import Core
+@testable import TestSupport
+
+protocol AddTwoNumbersTestCaseProvider: TestCaseProviding { }
+
+extension AddTwoNumbersTestCaseProvider {
+
+    func validateInput(_ input: (l1: ListNode?, l2: ListNode?)) -> Bool {
+        // TODO: Implement validation
+        true
+    }
+
+    var data: [TestData<(l1: ListNode?, l2: ListNode?), ListNode?>] { [
+        TestData(
+            input: ([2, 4, 3].listNode, [5, 6, 4].listNode),
+            expectedOutput: [7, 0, 8].listNode
+        ),
+        TestData(
+            input: ([0].listNode, [0].listNode),
+            expectedOutput: [0].listNode
+        ),
+        TestData(
+            input: ([9, 9, 9, 9, 9, 9, 9].listNode, [9, 9, 9, 9].listNode),
+            expectedOutput: [8, 9, 9, 9, 0, 0, 0, 1].listNode
+        )
+    ] }
+}