45 lines
912 B
Java
45 lines
912 B
Java
package sorts;
|
||
|
||
/**
|
||
* Created by wangzheng on 2018/10/16.
|
||
*/
|
||
public class QuickSort {
|
||
|
||
// 快速排序，a是数组，n表示数组的大小
|
||
public static void quickSort(int[] a, int n) {
|
||
quickSortInternally(a, 0, n-1);
|
||
}
|
||
|
||
// 快速排序递归函数，p,r为下标
|
||
private static void quickSortInternally(int[] a, int p, int r) {
|
||
if (p >= r) return;
|
||
|
||
int q = partition(a, p, r); // 获取分区点
|
||
quickSortInternally(a, p, q-1);
|
||
quickSortInternally(a, q+1, r);
|
||
}
|
||
|
||
private static int partition(int[] a, int p, int r) {
|
||
int pivot = a[r];
|
||
int i = p;
|
||
for(int j = p; j < r; ++j) {
|
||
if (a[j] < pivot) {
|
||
if (i == j) {
|
||
++i;
|
||
} else {
|
||
int tmp = a[i];
|
||
a[i++] = a[j];
|
||
a[j] = tmp;
|
||
}
|
||
}
|
||
}
|
||
|
||
int tmp = a[i];
|
||
a[i] = a[r];
|
||
a[r] = tmp;
|
||
|
||
System.out.println("i=" + i);
|
||
return i;
|
||
}
|
||
}
|