public static void quickSort(int[] arr, int left, int right) {
    var pivotIndex = left + (right - left) / 2;
    var pivotValue = arr[pivotIndex];
    var i = left;
    var j = right;
    while (i <= j) {
      while (arr[i] < pivotValue) {
        i++;
      }
      while (arr[j] > pivotValue) {
        j--;
      }
      if (i <= j) {
        var tmp = arr[i];
        arr[i] = arr[j];
        arr[j] = tmp;
        i++;
        j--;
      }
      if (left < i) {
        quickSort(arr, left, j);
      }
      if (right > i) {
        quickSort(arr, i, right);
      }
    }
  }

  public static void bubbleSort(int[] arr) {
    var lastIndex = arr.length - 1;

    for(var j = 0; j < lastIndex; j++) {
      for(var i = 0; i < lastIndex - j; i++) {
        if(arr[i] > arr[i + 1]) {
          var tmp = arr[i];
          arr[i] = arr[i + 1];
          arr[i + 1] = tmp;
        }
      }
    }
  }

  public static void selectionSort(int[] arr) {
    var len = arr.length;
        
    for (var i = 0; i < len - 1; i++) {
      var minIndex = i;
        
      for (var j = i + 1; j < len; j++) {
        if(arr[j] < arr[minIndex])
          minIndex = j;
      }
        
      var tmp = arr[minIndex];
      arr[minIndex] = arr[i];
      arr[i] = tmp;
    }
  }

  public static void insertionSort(int[] arr) {
    for (var i = 1; i < arr.length; i++) {
      var tmp = arr[i];
      var j = i - 1;

      while (j >= 0 && arr[j] > tmp) {
        arr[j + 1] = arr[j];
        j--;
      }
      arr[j + 1] = tmp;
    }
  }

  public static void countingSort(int[] arr) {
    var max = Arrays.stream(arr).max().getAsInt();

    var count = new int[max + 1];

    for (var num : arr) {
      count[num]++;
    }

    for (var i = 1; i <= max; i++) {
      count[i] += count[i - 1];
    }

    var sorted = new int[arr.length];
    for (var i = arr.length - 1; i >= 0; i--) {
      var cur = arr[i];
      sorted[count[cur] - 1] = cur;
      count[cur]--;
    }

    var index = 0;
    for (var num : sorted) {
      arr[index++] = num;
    }
  }

  public static <T> T[] arrayConcat(T[] first, T[] second) {
    var result = Arrays.copyOf(first, first.length + second.length);
    System.arraycopy(second, 0, result, first.length, se