关于下述C++代码的快速排序算法，说法错误的是（ ）。
int randomPartition(std::vector<int>& arr, int low, int high) { int random = low + rand() % (high - low + 1); std::swap(arr[random], arr[high]); int pivot = arr[high]; int i = low - 1; for (int j = low; j < high; j++) { if (arr[j] <= pivot) { i++; std::swap(arr[i], arr[j]); } } std::swap(arr[i + 1], arr[high]); return i + 1;} void quickSort(std::vector<int>& arr, int low, int high) { if (low < high) { int pi = randomPartition(arr, low, high); quickSort(arr, low, pi - 1); quickSort(arr, pi + 1, high); }}