Java中最常用的幾種算法如下：
- 選擇排序（selection sort）
- 插入排序（insertion sort）
- 冒泡排序（bubble sort）
- 快速排序（quick sort）
- 歸併排序（merge sort）
- 桶排序（bucket sort）
具體實現代碼如下：
public class NumberSort {
public static void main(String[] args) {
int[] selectionSortvalues = new int[] {9,10,6,5,0,7,8,3,2,4,1};
selectionSort(selectionSortvalues);
int[] insertionSortvalues = new int[] {9,10,6,5,0,7,8,3,2,4,1};
insertionSort(insertionSortvalues);
int[] bubbleSortvalues = new int[] {9,10,6,5,0,7,8,3,2,4,1};
bubbleSort(bubbleSortvalues);
int[] quickSortvalues= new int[] {9,10,6,5,0,7,8,3,2,4,1};
quickSort(quickSortvalues,0,quickSortvalues.length - 1);
System.out.print("\n快速排序：");
printValues(quickSortvalues);
int[] mergeSortvalues= new int[] {9,10,6,5,0,7,8,3,2,4,1};
mergeSort(mergeSortvalues,0,mergeSortvalues.length - 1);
System.out.print("\n歸併排序：");
printValues(mergeSortvalues);
int[] BucketSortvalues= new int[] {9,10,6,5,0,7,8,3,2,4,1};
BuckeSort(BucketSortvalues,10);
System.out.print("\n桶 排序：");
printValues(BucketSortvalues);
}
/**
* 選擇排序
* @param values
*/
public static void selectionSort(int[] values) {
System.out.print("選擇排序：");
if (values.length <= 1)
return;
int k,minIndex;
for (int i = 0; i < values.length; i++) {
minIndex = i;
for (k = i + 1; k < values.length; k++)
if (values[k] < values[minIndex])
minIndex = k;
int temp = values[minIndex];
values[minIndex] = values[i];
values[i] = temp;
}
printValues(values);
}
/**
* 插入排序
* @param values
*/
public static void insertionSort(int[] values) {
System.out.print("\n插入排序：");
if (values.length <= 1)
return;
int k,value;
for (int i = 1; i < values.length; i++) {
value = values[i];
k = i - 1;
while(k >= 0 && values[k] > value) {
values[k + 1] = values[k];
k = k - 1;
}
values[k + 1] = value;
}
printValues(values);
}
/**
* 冒泡排序
* @param values
*/
public static void bubbleSort(int[] values) {
System.out.print("\n冒泡排序：");
boolean swapped;
for (int i = 0; i < values.length; i++) {
swapped = false;
for (int j = values.length - 1; j > i; j--) {
if (values[j] < values[j - 1]) {
int temp = values[j];
values[j] = values[j - 1];
values[j - 1] = temp;
swapped = true;
}
}
if(swapped == false)
break;
}
printValues(values);
}
/**
* 快速排序
* @param values
* @param low
* @param hight
*/
public static void quickSort(int[] values,int low,int hight) {
/*
* int low = 0; int hight= values.length - 1;
*/
if (low < hight) {
int index = partition(values, low, hight);
quickSort(values,low, index - 1);
quickSort(values, index + 1, hight);
}
}
public static int partition(int[] values,int low,int hight) {
int privote = values[hight];
int i = low - 1;
for (int j = low; j <= hight - 1; j++) {
if(values[j] <= privote) {
i ++;
int temp = values[i];
values[i] = values[j];
values[j] = temp;
}
}
i ++;
int temp = values[i];
values[i] = values[hight];
values[hight] = temp;
return i;
}
public static void mergeSort(int[] values,int left,int right) {
if (left == right)
return;
if(left < right) {
int middle = (left + right) / 2;
mergeSort(values,left,middle);
mergeSort(values, middle + 1, right);
int[] temp = new int[values.length];
for (int i = left; i <= right; i++) {
temp[i] = values[i];
}
int index1 = left;
int index2 = middle + 1;
for (int i = left; i <= right; i++) {
if(index1 == middle + 1)
values[i] = temp[index2 ++];
else if(index2 > right)
values[i] = temp[index1 ++];
else if(temp[index1] < temp[index2])
values[i] = temp[index1 ++];
else
values[i] = temp[index2 ++];
}
}
}
/**
* 桶排序
* @param buckeSortvalues
* @param i
*/
private static void BuckeSort(int[] values, int maxVal) {
int[] bucket = new int[maxVal + 1];
int num = values.length;
int bucketNum = bucket.length;
for (int i = 0; i < bucketNum; i++) {
bucket[i] = 0;
}
for (int i = 0; i < num; i++) {
bucket[values[i]] ++;
}
int pos = 0;
for (int i = 0; i < bucketNum; i++) {
for (int j = 0; j < bucket[i]; j++) {
values[pos ++] = i;
}
}
}
public static void printValues(int[] values) {
for (int i = 0; i < values.length; i++) {
System.out.print(values[i] + ",");
}
}
}
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