归并排序模板

void merge(int[] arr, int start, int end) { if (start == end) return; int mid = (start + end) / 2; merge(arr, start, mid); merge(arr, mid + 1, end); int[] temp = new int[end - start + 1]; int i = start, j = mid + 1, k = 0; while(i <= mid && j <= end) temp[k++] = arr[i] < arr[j] ? arr[i++] : arr[j++]; while(i <= mid) temp[k++] = arr[i++]; while(j <= end) temp[k++] = arr[j++]; System.arraycopy(temp, 0, arr, start, end); }