[REFACTOR] Check null arguments

Author: Gonzalo Diaz

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/arrays/ArraysLeftRotation.cs

@@ -16,6 +16,8 @@ protected ArraysLeftRotation() { }
    */
   public static List<int> rotLeftOne(List<int> input)
   {
+    ArgumentNullException.ThrowIfNull(input);
+
     int first = input[FIRST_POSITION];
     input.RemoveAt(FIRST_POSITION);
     input.Add(first);
@@ -28,6 +30,8 @@ public static List<int> rotLeftOne(List<int> input)
    */
   public static List<int> rotLeft(List<int> input, int d)
   {
+    ArgumentNullException.ThrowIfNull(input);
+
     // Clone the list
     List<int> output = input.GetRange(FIRST_POSITION, input.Count);
 

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/arrays/CrushBruteForce.cs

@@ -14,6 +14,8 @@ protected CrushBruteForce() { }
 
   public static long arrayManipulation(int n, List<List<int>> queries)
   {
+    ArgumentNullException.ThrowIfNull(queries);
+
     // why adding 1?
     //   first slot to adjust 1-based index and
     int[] result = new int[n + 1];

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/arrays/CrushOptimized.cs

@@ -15,6 +15,8 @@ private CrushOptimized() { }
    */
   public static long arrayManipulation(int n, List<List<int>> queries)
   {
+    ArgumentNullException.ThrowIfNull(queries);
+
     // why adding 2?
     //   first slot to adjust 1-based index and
     //   last slot for storing accumSum result

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/arrays/NewYearChaos.cs

@@ -2,20 +2,17 @@
 
 namespace algorithm_exercises_csharp.hackerrank.interview_preparation_kit.arrays;
 
-using System.Diagnostics.CodeAnalysis;
-
-public class NewYearChaos
+public static class NewYearChaos
 {
-  [ExcludeFromCodeCoverage]
-  protected NewYearChaos() { }
-
-  public const String TOO_CHAOTIC_ERROR = "Too chaotic";
+  public const string TOO_CHAOTIC_ERROR = "Too chaotic";
 
   /**
    * minimumBribesCalculate.
    */
   public static int minimumBribesCalculate(List<int> q)
   {
+    ArgumentNullException.ThrowIfNull(q);
+
     int bribes = 0;
     int i = 0;
 

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/arrays/TwoDArray.cs

@@ -31,6 +31,8 @@ private static List<int> getHourGlass(List<List<int>> arr, int positionX, int po
 
   public static int hourglassSum(List<List<int>> arr)
   {
+    ArgumentNullException.ThrowIfNull(arr);
+
     int matrixSize = arr.Count;
 
     int matrixStartIndex = 1;

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/dictionaries_and_hashmaps/CountTriplets.cs

@@ -4,7 +4,6 @@
 
 namespace algorithm_exercises_csharp.hackerrank.interview_preparation_kit.dictionaries_and_hashmaps;
 
-using System.Diagnostics.CodeAnalysis;
 using System.Collections.Generic;
 
 public class CountTriplets
@@ -14,6 +13,8 @@ protected CountTriplets() { }
 
   public static long countTriplets(List<long> arr, long r)
   {
+    ArgumentNullException.ThrowIfNull(arr);
+
     Dictionary<long, long> aCounter = [];
     Dictionary<long, long> bCounter = [];
     long triplets = 0L;

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/dictionaries_and_hashmaps/CountTripletsBruteForce.cs

@@ -12,6 +12,8 @@ protected CountTripletsBruteForce() { }
 
   public static long countTriplets(List<long> arr, long r)
   {
+    ArgumentNullException.ThrowIfNull(arr);
+
     long size = arr.Count;
     long counter = 0L;
 

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/dictionaries_and_hashmaps/FrequencyQueries.cs

@@ -116,6 +116,8 @@ void select(long value)
    */
   public static List<int> freqQuery(List<List<int>> queries)
   {
+    ArgumentNullException.ThrowIfNull(queries);
+
     FrequencyQueries fq = new();
 
     foreach (List<int> query in queries)

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/dictionaries_and_hashmaps/RansomNote.cs

@@ -24,6 +24,9 @@ public InvalidValueException(string msg)
 
   public static bool checkMagazineCompute(List<string> magazine, List<string> note)
   {
+    ArgumentNullException.ThrowIfNull(magazine);
+    ArgumentNullException.ThrowIfNull(note);
+
     Dictionary<string, int> dictionary = [];
 
     foreach (string word in magazine)

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/dictionaries_and_hashmaps/SherlockAndAnagrams.cs

@@ -26,6 +26,8 @@ public static BigInteger factorial(int number)
 
   public static int sherlockAndAnagrams(string s)
   {
+    ArgumentException.ThrowIfNullOrEmpty(s);
+
     Dictionary<string, List<string>> candidates = [];
 
     int size = s.Length;

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/dictionaries_and_hashmaps/TwoStrings.cs

@@ -15,7 +15,10 @@ protected TwoStrings() { }
 
   public static bool twoStringsCompute(string s1, string s2)
   {
-    char occurrence = s1.FirstOrDefault(c => s2.Contains(c), __EMPTY_CHAR__);
+    ArgumentException.ThrowIfNullOrEmpty(s1);
+    ArgumentException.ThrowIfNullOrEmpty(s2);
+
+    char occurrence = s1.FirstOrDefault(s2.Contains, __EMPTY_CHAR__);
 
     if (occurrence != __EMPTY_CHAR__)
     {

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/greedy_algorithms/LuckBalance.cs

@@ -17,6 +17,8 @@ protected LuckBalance() { }
 
   public static int luckBalance(int k, List<List<int>> contests)
   {
+    ArgumentNullException.ThrowIfNull(contests);
+
     List<Competition> important_competitions = [];
     List<Competition> nonimportant_competitions = [];
 

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/greedy_algorithms/MinimumAbsoluteDifferenceInAnArray.cs

@@ -16,6 +16,8 @@ private MinimumAbsoluteDifferenceInAnArray()
    */
   public static int minimumAbsoluteDifference(List<int> arr)
   {
+    ArgumentNullException.ThrowIfNull(arr);
+
     List<int> sortedNums = [.. arr.ConvertAll(x => x).OrderBy(x => x).ToList()];
 
     // Find the minimum absolute difference

src/algorithm_exercises_csharp/hackerrank/warmup/AVeryBigSum.cs

@@ -2,18 +2,15 @@
 
 namespace algorithm_exercises_csharp.hackerrank.warmup;
 
-using System.Diagnostics.CodeAnalysis;
-
-public class AVeryBigSum
+public static class AVeryBigSum
 {
-  [ExcludeFromCodeCoverage]
-  protected AVeryBigSum() { }
-
-  public static long aVeryBigSum(List<long> _ar)
+  public static long aVeryBigSum(List<long> ar)
   {
+    ArgumentNullException.ThrowIfNull(ar);
+
     var total = 0L;
 
-    foreach (long x in _ar)
+    foreach (long x in ar)
     {
       total += x;
     }

src/algorithm_exercises_csharp/hackerrank/warmup/BirthdayCakeCandles.cs

@@ -11,6 +11,8 @@ protected BirthdayCakeCandles() { }
 
   public static int birthdayCakeCandles(List<int> _arr)
   {
+    ArgumentNullException.ThrowIfNull(_arr);
+
     if (_arr.Count == 0)
     {
       throw new ArgumentException("Parameter cannot be empty", nameof(_arr));

src/algorithm_exercises_csharp/hackerrank/warmup/CompareTriplets.cs

@@ -11,6 +11,9 @@ protected CompareTriplets() { }
 
   public static List<int> compareTriplets(List<int> _a, List<int> _b)
   {
+    ArgumentNullException.ThrowIfNull(_a);
+    ArgumentNullException.ThrowIfNull(_b);
+
     List<int> awards = [0, 0];
 
     for (int i = 0; i < _a.Count; i++)

src/algorithm_exercises_csharp/hackerrank/warmup/DiagonalDifference.cs

@@ -11,6 +11,8 @@ protected DiagonalDifference() { }
 
   public static int diagonalDifference(List<List<int>> _arr)
   {
+    ArgumentNullException.ThrowIfNull(_arr);
+
     int diag1 = 0;
     int diag2 = 0;
     int last = _arr.Count - 1;