下述C++代码实现了归并排序算法，则横线上应填写（ ）。
void merge(vector<int> &nums, int left, int mid, int right) { // 左子数组区间为 [left, mid], 右子数组区间为 [mid+1, right] vector<int> tmp(right - left + 1); int i = left, j = mid + 1, k = 0; while (i <= mid && j <= right) { if (nums[i] <= nums[j]) tmp[k++] = nums[i++]; else tmp[k++] = nums[j++]; } while (i <= mid) { tmp[k++] = nums[i++]; } while (________) { // 在此处填入代码 tmp[k++] = nums[j++]; } for (k = 0; k < tmp.size(); k++) { nums[left + k] = tmp[k]; }} void mergeSort(vector<int> &nums, int left, int right) { if (left >= right) return; int mid = (left + right) / 2; mergeSort(nums, left, mid); mergeSort(nums, mid + 1, right); merge(nums, left, mid, right);}