快速排序

// 快速排序static void sort2(int a[], int l, int r) {if (l < r) {int mid = pa(a, l, r);sort2(a, l, mid - 1);sort2(a, mid + 1, r);}return;}private static int pa(int[] a, int l, int r) {// TODO Auto-generated method stubint tmp = a[l];while (l < r) {while (l < r && a[r] > tmp) {r--;}swap(a, l, r);while (l < r && a[l] < tmp) {l++;}swap(a, l, r);}System.out.println(Arrays.toString(a));return l;}static void swap(int a[], int x, int y) {int tmp;tmp = a[x];a[x] = a[y];a[y] = tmp;}