收藏快速排序
/**
* 改进后的快速排序:
*
*/
public class ImprovedQuickSort {
private static int MAX_STACK_SIZE = 4096;
private static int THRESHOLD = 10;
public void sort(int[] data) {
int[] stack = new int[MAX_STACK_SIZE];
int top = -1;
int pivot;
int pivotIndex, l, r;
stack[++top] = 0;
stack[++top] = data.length - 1;
while (top > 0) {
int j = stack[top--];
int i = stack[top--];
pivotIndex = (i + j) / 2;
pivot = data[pivotIndex];
swap(data, pivotIndex, j);
// partition
l = i - 1;
r = j;
do {
while (data[++l] < pivot)
;
while ((r != 0) && (data[--r] > pivot))
;
swap(data, l, r);
} while (l < r);
swap(data, l, r);
swap(data, l, j);
if ((l - i) > THRESHOLD) {
stack[++top] = i;
stack[++top] = l - 1;
}
if ((j - l) > THRESHOLD) {
stack[++top] = l + 1;
stack[++top] = j;
}
}
// new InsertSort().sort(data);
insertSort(data);
}
/**
* @param data
*/
private void insertSort(int[] data) {
for (int i = 1; i < data.length; i++) {
for (int j = i; (j > 0) && (data[j] < data[j - 1]); j--) {
swap(data, j, j - 1);
}
}
}
private void swap(int[] data, int i, int j) {
int temp = data[i];
data[i] = data[j];
data[j] = temp;
}
}
Java代码 收藏代码
/**
* 快速排序:
*
*/
public class QuickSort {
public void sort(int[] data) {
quickSort(data, 0, data.length - 1);
}
private void quickSort(int[] data, int i, int j) {
int pivotIndex = (i + j) / 2;
// swap
swap(data, pivotIndex, j);
int k = partition(data, i - 1, j, data[j]);
swap(data, k, j);
if ((k - i) > 1)
quickSort(data, i, k - 1);
if ((j - k) > 1)
quickSort(data, k + 1, j);
}
/**
* @param data
* @param l
* @param r
* @param pivot
* @return
*/
private int partition(int[] data, int l, int r, int pivot) {
do {
while (data[++l] < pivot)
;
while ((r != 0) && data[--r] > pivot)
;
swap(data, l, r);
} while (l < r);
swap(data, l, r);
return l;
}
private void swap(int[] data, int i, int j) {
int temp = data[i];
data[i] = data[j];
data[j] = temp;
}
}