堆排序算法参考了下面的文章,在他的基础上改进了一点,原来有几个地方循环次数多了 https://www.cnblogs.com/Java3y/p/8639937.html
public class TestThird {
private static int[] ss = {334, 4, 532, 24, 147, 76, 735, 245, 734, 2356, 24, 334, 735};
public static void main(String[] args) {
int len = ss.length;
for (int i = 0; i < len; i++) {
System.out.print(" " + ss[i]);
}
System.out.println(" ");
// heapSort(ss, len);
// sort(0, len - 1);
// bubbleSort(ss, len);
shellSort(len);
for (int i = 0; i < len; i++) {
System.out.print(" " + ss[i]);
}
}
//冒泡排序 思想是相邻两个数两两比较,经过一轮排序确认一个最大值,下轮循环就少循环一次
private static void bubbleSort(int[] aa, int len) {
for (int i = 0; i < len; i++) {
for (int j = 1; j < len - i; j++) {
if (aa[j] < aa[j - 1]) {
int temp = aa[j - 1];
aa[j - 1] = aa[j];
aa[j] = temp;
}
}
}
}
//快速排序 思想找一个基准,通常选数组中的第一个元素,把比基准大的放在他的右边,比基准小的放在它的左边,
//最后基准的位置找到,这时,由基准的位置把数组分成了两部分,从新用上面方法,用到递归方法。
private static void sort(int left, int right) {
if (left >= right) {
return;
}
int index = quickSort(left, right);
sort(index + 1, right);
sort(left, index - 1);
}
//快速排序的步骤
private static int quickSort(int left, int right) {
int key = ss[left];
while (left < right) {
while (left < right && ss[right] >= key) {
right--;
}
ss[left] = ss[right];
while (left < right && ss[left] <= key) {
left++;
}
ss[right] = ss[left];
}
ss[left] = key;
return left;
}
//堆排序 堆排序算法参考了下面的文章,在他的基础上改进了一点,原来有几个地方循环次数多了 // https://www.cnblogs.com/Java3y/p/8639937.html private static void heapSort(int[] arr, int len) {
madHeap(arr, len);
int currentMaxIndex = len - 1;
for (int i = 0; i < len; i++) {
int temp = arr[0];
arr[0] = arr[len - 1 - i];
arr[len - 1 - i] = temp;
heapAdjust(arr, 0, currentMaxIndex);
currentMaxIndex--;
}
}
//堆排序构建大根堆
private static void madHeap(int[] arr, int size) {
for (int i = (size - 1) / 2; i >= 0; i--) {
heapAdjust(arr, i, size);
}
}
//调整堆使之成为大根堆
private static void heapAdjust(int[] arr, int index, int size) {
int left = index * 2 + 1;
int right = index * 2 + 2;
int max = index;
if (left < size) {
if (arr[max] < arr[left]) {
max = left;
}
}
if (right < size) {
if (arr[max] < arr[right]) {
max = right;
}
}
if (max != index) {
int temp = arr[index];
arr[index] = arr[max];
arr[max] = temp;
heapAdjust(arr, max, size);
}
}
//希尔排序
private static void shellSort(int len) {
int temp = 0;
int d = len;
//下面的两个while循环 都是希尔排序的实现,只是想法不一样,插入的方式不同 第一个循环次数少
while (true) {
d = d / 2;
for (int i = d; i < len; i++) {
for (int j = i; j >= d; j = j - d) {
if (ss[j] < ss[j - d]) {
temp = ss[j];
ss[j] = ss[j - d];
ss[j - d] = temp;
}
}
}
if (d == 1) {
break;
}
}
while (true) {
d = d / 2;
for (int i = 0; i < d; i++) {
for (int j = i + d; j < len; j = j + d) {
for (int k = j - d; k >= 0; k = k - d) {
if (ss[k + d] < ss[k]) {
temp = ss[k];
ss[k] = ss[k + d];
ss[k + d] = temp;
}
}
}
}
if (d == 1) {
break;
}
}
}
}