Added new solutions and tests

Author: Michael-Ho-Bose

Easy/0067-AddBinary.playground/Contents.swift

@@ -0,0 +1,68 @@
+// LeetCode: https://leetcode.com/problems/add-binary/description/
+
+import XCTest
+
+class Solution {
+    func addBinary(_ a: String, _ b: String) -> String {
+        var arrA = Array(a.reversed())
+        var arrB = Array(b.reversed())
+        var shouldAdd = 0
+        var output = ""
+        for idx in 0..<max(arrA.count, arrB.count) {
+            var valA = 0
+            var valB = 0
+            if idx < arrA.count {
+                valA = Int(String(arrA[idx]))!
+            }
+            if idx < arrB.count {
+                valB = Int(String(arrB[idx]))!
+            }
+            if valA + valB + shouldAdd > 1 {
+                output.append("\(valA + valB + shouldAdd - 2)")
+                shouldAdd = 1
+            } else {
+                output.append("\(valA + valB + shouldAdd)")
+                shouldAdd = 0
+            }
+        }
+        if shouldAdd == 1 {
+            output.append("1")
+        }
+        output = String(output.reversed())
+        return output
+    }
+}
+
+class Tests: XCTestCase {
+    let s = Solution()
+    
+    func testSample1() {
+        let input = ("1010", "1011")
+        let expected = "10101"
+        let output = s.addBinary(input.0, input.1)
+        XCTAssertEqual(expected, output)
+    }
+    
+    func testSample2() {
+        let input = ("11", "1")
+        let expected = "100"
+        let output = s.addBinary(input.0, input.1)
+        XCTAssertEqual(expected, output)
+    }
+    
+    func testSample3() {
+        let input = ("0", "0")
+        let expected = "0"
+        let output = s.addBinary(input.0, input.1)
+        XCTAssertEqual(expected, output)
+    }
+    
+    func testSample4() {
+        let input = ("101", "110")
+        let expected = "1011"
+        let output = s.addBinary(input.0, input.1)
+        XCTAssertEqual(expected, output)
+    }
+}
+
+Tests.defaultTestSuite.run()

Easy/0067-AddBinary.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='macos'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

Medium/0003-LongestSubstringWithoutRepeatingCharacters.playground/Contents.swift

@@ -1,4 +1,7 @@
 // LeetCode: https://leetcode.com/problems/longest-substring-without-repeating-characters/description/
+// Note: Use Set() to solve the problem: time limit exceeded.
+
+import XCTest
 
 class Solution {
     func lengthOfLongestSubstring(_ s: String) -> Int {
@@ -27,5 +30,20 @@ class Solution {
     }
 }
 
-let s = Solution()
-print("\(s.lengthOfLongestSubstring("dvdf"))")
+class Tests: XCTestCase {
+    let solution = Solution()
+    
+    func testSample1() {
+        let sample = "dvdf"
+        let expected = 3
+        XCTAssertEqual(solution.lengthOfLongestSubstring(sample), expected)
+    }
+    
+    func testSample2() {
+        let sample = "abcabcbb"
+        let expected = 3
+        XCTAssertEqual(solution.lengthOfLongestSubstring(sample), expected)
+    }
+}
+
+Tests.defaultTestSuite.run()

Medium/0006-ZigZagConversion.playground/Contents.swift

@@ -1,5 +1,7 @@
 // LeetCode: https://leetcode.com/problems/zigzag-conversion/description/
 
+import XCTest
+
 class Solution {
     func convert(_ s: String, _ numRows: Int) -> String {
         var output = ""
@@ -24,6 +26,20 @@ class Solution {
     }
 }
 
-let solution = Solution()
-print("\(solution.convert("PAYPALISHIRING", 3))")
-print("\(solution.convert("PAYPALISHIRING", 4))")
+class Tests: XCTestCase {
+    let solution = Solution()
+    
+    func testSample1() {
+        let input = ("PAYPALISHIRING", 4)
+        let expected = "PINALSIGYAHRPI"
+        XCTAssertEqual(solution.convert(input.0, input.1), expected)
+    }
+    
+    func testSample2() {
+        let input = ("PAYPALISHIRING", 3)
+        let expected = "PAHNAPLSIIGYIR"
+        XCTAssertEqual(solution.convert(input.0, input.1), expected)
+    }
+}
+
+Tests.defaultTestSuite.run()

Medium/0011-ContainerWithMostWater.playground/Contents.swift

@@ -1,16 +1,15 @@
 // LeetCode: https://leetcode.com/problems/container-with-most-water/description/
+// Try to use O(n) runtime
+
+import XCTest
 
 class Solution {
     func maxArea(_ height: [Int]) -> Int {
         var area = 0
         var start = 0
         var end = height.count - 1
         while start < end {
-            let areaH = min(height[start], height[end])
-            let width = end - start
-            if areaH * width > area {
-                area = areaH * width
-            }
+            area = max(area, min(height[start], height[end]) * (end - start))
             if height[start] < height[end] {
                 start += 1
             } else {
@@ -21,5 +20,14 @@ class Solution {
     }
 }
 
-let solution = Solution()
-print("\(solution.maxArea([1,8,6,2,5,4,8,3,7]))") // 49
+class Tests: XCTestCase {
+    let solution = Solution()
+    
+    func testSample() {
+        let intput = [1,8,6,2,5,4,8,3,7]
+        let expected = 49
+        XCTAssertEqual(solution.maxArea(intput), expected)
+    }
+}
+
+Tests.defaultTestSuite.run()

Medium/0012-IntegerToRoman.playground/Contents.swift

@@ -10,6 +10,8 @@
  1000 : "M"
  */
 
+import XCTest
+
 class Solution {
     func intToRoman(_ num: Int) -> String {
         var output = ""
@@ -63,9 +65,38 @@ class Solution {
     }
 }
 
-let solution = Solution()
-print("\(solution.intToRoman(3))")
-print("\(solution.intToRoman(4))")
-print("\(solution.intToRoman(9))")
-print("\(solution.intToRoman(58))")
-print("\(solution.intToRoman(1994))")
+class Tests: XCTestCase {
+    let solution = Solution()
+    
+    func sampleTest1() {
+        let input = 3
+        let expected = "III"
+        XCTAssertEqual(solution.intToRoman(input), expected)
+    }
+    
+    func sampleTest2() {
+        let input = 4
+        let expected = "IV"
+        XCTAssertEqual(solution.intToRoman(input), expected)
+    }
+
+    func sampleTest3() {
+        let input = 9
+        let expected = "IX"
+        XCTAssertEqual(solution.intToRoman(input), expected)
+    }
+
+    func sampleTest4() {
+        let input = 58
+        let expected = "LVIII"
+        XCTAssertEqual(solution.intToRoman(input), expected)
+    }
+
+    func sampleTest5() {
+        let input = 1994
+        let expected = "MCMXCIV"
+        XCTAssertEqual(solution.intToRoman(input), expected)
+    }
+}
+
+Tests.defaultTestSuite.run()

Medium/0015-3Sum.playground/Contents.swift

@@ -1,5 +1,7 @@
 // LeetCode: https://leetcode.com/problems/3sum/description/
-// Hint: Start from TwoSum, use sorting
+// Hint: Start from TwoSum, use sorting, O(n) is allowed in runtime
+
+import XCTest
 
 class Solution {
     func threeSum(_ nums: [Int]) -> [[Int]] {
@@ -19,67 +21,102 @@ class Solution {
                     output.append([sort[i], sort[start], sort[end]])
                     start += 1
                     end -= 1
+                    while start < end, start - 1 >= 0, sort[start] == sort[start - 1] {
+                        start += 1
+                    }
+                    while start < end, end + 1 < sort.count, sort[end] == sort[end + 1] {
+                        end -= 1
+                    }
                 } else if sort[i] + sort[start] + sort[end] < 0 {
                     start += 1
                 } else {
                     end -= 1
                 }
-                if start - 1 >= 0 && sort[start] == sort[start - 1] {
-                    start += 1
-                    continue
-                }
-                if end + 1 < sort.count && sort[end] == sort[end + 1] {
-                    end -= 1
-                    continue
-                }
             }
         }
         return output
     }
 }
 
-let solution = Solution()
-print("\(solution.threeSum([-1, 0, 1, 2, -1, -4]))")
-print("---------------------------------")
-/**
- The solution set is:
- [
-    [-1, 0, 1],
-    [-1, -1, 2]
- ]
- */
-print("\(solution.threeSum([-1,0,1,0]))")
-print("---------------------------------")
-/**
- The solution set is:
- [
-    [-1, 0, 1]
- ]
- */
-print("\(solution.threeSum([3,0,-2,-1,1,2]))")
-print("---------------------------------")
-/**
- The solution set is:
- [
-    [-2, -1, 3],
-    [-2, 0, 2],
-    [-1, 0, 1]
- ]
- */
-print("\(solution.threeSum([-2,0,1,1,2]))")
-/**
- The solution set is:
- [
-    [-2,0,2],
-    [-2,1,1]
- ]
- */
-print("\(solution.threeSum([1,1,1]))") // [[]]
-let longArray1 = [-2,10,-14,11,5,-4,2,0,-10,-10,5,7,-11,10,-2,-5,2,12,-5,14,-11,-15,-5,12,0,13,8,7,10,6,-9,-15,1,14,11,-9,-13,-10,6,-8,-5,-11,6,-9,14,11,-7,-6,8,3,-7,5,-5,3,2,10,-6,-12,3,11,1,1,12,10,-8,0,8,-5,6,-8,-6,8,-12,-14,7,9,12,-15,-12,-2,-4,-4,-12,6,7,-3,-6,-14,-8,4,4,9,-10,-7,-4,-3,1,11,-1,-8,-12,9,7,-9,10,-1,-14,-1,-8,11,12,-5,-7]
-print(longArray1.count)
-print("\(solution.threeSum(longArray1))") // Test time limit
-print("---------------------------------")
-let longArray2 = [12,-14,-5,12,-2,9,0,9,-3,-3,-14,-6,-4,13,-11,-8,0,5,-7,-6,-10,-13,-7,-14,-3,0,12,5,-8,7,3,-11,0,6,9,13,-8,-6,7,4,6,0,13,-13,-1,9,-13,6,-1,-13,-15,-4,-11,-15,-11,-7,1,-14,13,8,0,2,4,-15,-15,-2,5,-8,7,-11,11,-10,4,1,-15,10,-5,-13,2,1,11,-6,4,-15,-5,8,-7,3,1,-9,-4,-14,0,-15,8,0,-1,-2,7,13,2,-5,11,13,11,11]
-print(longArray2.count)
-print("\(solution.threeSum(longArray2))") // Test time limit
-print("---------------------------------")
+class Tests: XCTestCase {
+    let s = Solution()
+    
+    func testSample1() {
+        let input = [-4,-2,-2,-2,0,1,2,2,2,3,3,4,4,6,6]
+        let expected = [
+            [-4,-2,6],
+            [-4,0,4],
+            [-4,1,3],
+            [-4,2,2],
+            [-2,-2,4],
+            [-2,0,2]
+        ]
+        let output = s.threeSum(input)
+        XCTAssertEqual(output.count, expected.count)
+        for o in output {
+            XCTAssertTrue(expected.contains(o))
+        }
+    }
+    
+    func testSample2() {
+        let input = [0,0,0]
+        let expected = [[0,0,0]]
+        let output = s.threeSum(input)
+        XCTAssertEqual(output.count, expected.count)
+        for o in output {
+            XCTAssertTrue(expected.contains(o))
+        }
+    }
+    
+    func testSample3() {
+        let input = [-2,0,1,1,2]
+        let expected = [
+            [-2,0,2],
+            [-2,1,1]
+        ]
+        let output = s.threeSum(input)
+        XCTAssertEqual(output.count, expected.count)
+        for o in output {
+            XCTAssertTrue(expected.contains(o))
+        }
+    }
+    
+    func testSample4() {
+        let input = [3,0,-2,-1,1,2]
+        let expected = [
+            [-2, -1, 3],
+            [-2, 0, 2],
+            [-1, 0, 1]
+        ]
+        let output = s.threeSum(input)
+        XCTAssertEqual(output.count, expected.count)
+        for o in output {
+            XCTAssertTrue(expected.contains(o))
+        }
+    }
+    
+    func testSample5() {
+        let input = [-1,0,1,0]
+        let expected = [[-1, 0, 1]]
+        let output = s.threeSum(input)
+        XCTAssertEqual(output.count, expected.count)
+        for o in output {
+            XCTAssertTrue(expected.contains(o))
+        }
+    }
+    
+    func testSample6() {
+        let input = [-1, 0, 1, 2, -1, -4]
+        let expected = [
+            [-1, 0, 1],
+            [-1, -1, 2]
+        ]
+        let output = s.threeSum(input)
+        XCTAssertEqual(output.count, expected.count)
+        for o in output {
+            XCTAssertTrue(expected.contains(o))
+        }
+    }
+}
+
+Tests.defaultTestSuite.run()