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| // 冒泡排序策略
class BubbleSortStrategy implements SortStrategy {
@Override
public void sort(int[] array) {
System.out.println("使用冒泡排序...");
int n = array.length;
for (int i = 0; i < n - 1; i++) {
for (int j = 0; j < n - i - 1; j++) {
if (array[j] > array[j + 1]) {
// 交换元素
int temp = array[j];
array[j] = array[j + 1];
array[j + 1] = temp;
}
}
}
}
@Override
public String getStrategyName() {
return "冒泡排序";
}
}
// 快速排序策略
class QuickSortStrategy implements SortStrategy {
@Override
public void sort(int[] array) {
System.out.println("使用快速排序...");
quickSort(array, 0, array.length - 1);
}
private void quickSort(int[] arr, int low, int high) {
if (low < high) {
int pi = partition(arr, low, high);
quickSort(arr, low, pi - 1);
quickSort(arr, pi + 1, high);
}
}
private int partition(int[] arr, int low, int high) {
int pivot = arr[high];
int i = (low - 1);
for (int j = low; j < high; j++) {
if (arr[j] <= pivot) {
i++;
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
int temp = arr[i + 1];
arr[i + 1] = arr[high];
arr[high] = temp;
return i + 1;
}
@Override
public String getStrategyName() {
return "快速排序";
}
}
// 归并排序策略
class MergeSortStrategy implements SortStrategy {
@Override
public void sort(int[] array) {
System.out.println("使用归并排序...");
mergeSort(array, 0, array.length - 1);
}
private void mergeSort(int[] arr, int left, int right) {
if (left < right) {
int mid = (left + right) / 2;
mergeSort(arr, left, mid);
mergeSort(arr, mid + 1, right);
merge(arr, left, mid, right);
}
}
private void merge(int[] arr, int left, int mid, int right) {
int n1 = mid - left + 1;
int n2 = right - mid;
int[] leftArr = new int[n1];
int[] rightArr = new int[n2];
System.arraycopy(arr, left, leftArr, 0, n1);
System.arraycopy(arr, mid + 1, rightArr, 0, n2);
int i = 0, j = 0, k = left;
while (i < n1 && j < n2) {
if (leftArr[i] <= rightArr[j]) {
arr[k] = leftArr[i];
i++;
} else {
arr[k] = rightArr[j];
j++;
}
k++;
}
while (i < n1) {
arr[k] = leftArr[i];
i++;
k++;
}
while (j < n2) {
arr[k] = rightArr[j];
j++;
k++;
}
}
@Override
public String getStrategyName() {
return "归并排序";
}
}
|