Reorganize folders

Author: Michael Ho

Easy/EasyProblems.playground/Contents.swift

@@ -0,0 +1,54 @@
+// LeetCode: https://leetcode.com/problems/broken-calculator/
+// Hint: Operate from Y is easier
+
+
+import XCTest
+
+class Solution {
+    func brokenCalc(_ X: Int, _ Y: Int) -> Int {
+        if X >= Y {
+            return X-Y
+        } else {
+            // Reverse the operation from X to Y, available operations:
+            // 1. plus 1: +1
+            // 2. divide by 2: /2
+            return Y%2 == 0 ? 1+brokenCalc(X, Y/2) : 2+brokenCalc(X, (Y+1)/2)
+        }
+    }
+}
+
+class Tests: XCTestCase {
+    let s = Solution()
+    
+    func testSample1() {
+        let input = (2, 3)
+        let expected = 2
+        XCTAssertEqual(expected, s.brokenCalc(input.0, input.1))
+    }
+    
+    func testSample2() {
+        let input = (5, 8)
+        let expected = 2
+        XCTAssertEqual(expected, s.brokenCalc(input.0, input.1))
+    }
+    
+    func testSample3() {
+        let input = (3, 10)
+        let expected = 3
+        XCTAssertEqual(expected, s.brokenCalc(input.0, input.1))
+    }
+    
+    func testSample4() {
+        let input = (1, 1000000000)
+        let expected = 39
+        XCTAssertEqual(expected, s.brokenCalc(input.0, input.1))
+    }
+    
+    func testSample5() {
+        let input = (1024, 1)
+        let expected = 1023
+        XCTAssertEqual(expected, s.brokenCalc(input.0, input.1))
+    }
+}
+
+Tests.defaultTestSuite.run()

Medium/0043-MultiplyStrings.playground/Contents.swift

@@ -4,31 +4,6 @@
 import XCTest
 
 class Solution {
-//    func lengthOfLongestSubstring(_ s: String) -> Int {
-//        guard s.count > 0 else {
-//            return 0
-//        }
-//
-//        var maxCount = 1
-//        if s.count == 1 {
-//            return maxCount
-//        }
-//        let strArr = Array(s) // Key: convert string to array
-//        for (index, char) in strArr.enumerated() {
-//            var dict: [Character : Int] = [:]
-//            var count = 1
-//            dict[char] = 1
-//            var movingIdx = index + 1
-//            while movingIdx < strArr.count, dict[strArr[movingIdx]] ?? 0 < 1 {
-//                dict[strArr[movingIdx]] = 1
-//                count += 1
-//                movingIdx += 1
-//            }
-//            maxCount = count > maxCount ? count : maxCount
-//        }
-//        return maxCount
-//    }
-    // 14
     func lengthOfLongestSubstring(_ s: String) -> Int {
         let arr = Array(s)
         var dict = [Character : Int]() // [char : idx]