六大经典排序算法（Java版）：冒泡、选择、插入、希尔、快速、归并

/**
* @author Darren
* @Date 2016-10-17
*/
public class Main {

public static void main(String[] args) {
int[] ars = {2, 5, 9, 13, 28, 79, 2, 87};
System.out.println("Original Array:");
myPrintArray(ars);
int[] ars1 = myBubbleSort(ars);
System.out.println("BubbleSort:");
myPrintArray(ars1);

int[] ars2 = myChooseSort(ars);
System.out.println("ChooseSort:");
myPrintArray(ars2);

int[] ars3 = myInsertSort(ars);
System.out.println("InsertSort:");
myPrintArray(ars3);

int[] ars4 = myShellSort(ars);
System.out.println("ShellSort:");
myPrintArray(ars4);

myFastSort(ars, 0,ars.length-1);
System.out.println("FastSort:");
myPrintArray(ars);

int[] ars11 = {2, 5, 9, 87, 28, 79, 2, 13};
myMergeSort(ars11, 0, ars11.length-1);
System.out.println("MergeSort:");
myPrintArray(ars11);
}
/**
* @param ars the input array
*/
public static void myPrintArray(int[] ars) {
for(int a: ars) {
System.out.print(a+" ");
}
System.out.println();
}
/**
* @param ars the input array
* @return ars the bubble sorted array
*/
private static int[] myBubbleSort(int[] ars) {
int i, j, temp;
for(i=0; i<ars.length; i++) {
for(j=ars.length-1; j>i; j--) {
if(ars[j]<ars[j-1]) {
temp = ars[j];
ars[j] = ars[j-1];
ars[j-1] = temp;
}
}
}
return ars;
}
/**
* @param ars the input array
* @return ars the sorted array
*/
public static int[] myChooseSort(int[] ars) {
int i, j, index, temp;
for(i=0; i<ars.length; i++) {
index = i;
for(j=i+1; j<ars.length; j++) {
if(ars[j]<ars[index]) {
index = j;
}
}
temp = ars[index];
ars[index] = ars[i];
ars[i] = temp;
}
return ars;
}
/**
* @param ars the input array
* @return ars the sorted array
*/
public static int[] myInsertSort(int[] ars) {
int i, j, ai;
for(i=1; i<ars.length; i++) {
ai = ars[i];
for(j=i-1; j>=0; j--) {
if(ars[j]>ai) {
ars[j+1] = ars[j];
}else {
break;
}
}
ars[j+1] = ai;
}
return ars;
}
/**
* @param ars the input array
* @return ars the sorted array
*/
public static int[] myShellSort(int[] ars) {
int i, j, ai, d=1;
while(9*d<ars.length) {
d=3*d+1;
}
while(d>0) {
for(i=d; i<ars.length; i++) {
ai = ars[i];
for(j=i-d; j>=0; j-=d) {
if(ars[j]>ai) {
ars[j+d] = ars[j];
}else {
break;
}
}
ars[j+d] = ai;
}
d/=3;
}
return ars;
}
/**
* @param ars the input array
* @param start the start index of ars
* @param end the end index of ars
* @param basicValue the compared value of fast sorting method
* @return ars the sorted array
*/
public static void myFastSort(int[] ars, int start, int end) {
if(start<end) {
int i=start, j=end, basicValue=ars[start];
while(i<j) {
while(i<j && ars[j]>=basicValue) {  j--;}
if(i<j) {   ars[i] =  ars[j];}
while(i<j && ars[i]<=basicValue) {  i++;}
if(i<j) {   ars[j] = ars[i];}
}
ars[i] = basicValue;
myFastSort(ars, start, i-1);
myFastSort(ars, j+1, end);
}
}
/**
* @param ars the input array
* @param start the start index of ars
* @param end the end index of ars
* @param middle the middle index of merge sorting method
* @return ars the sorted array
*/
public static void myMergeSort(int[] ars, int start, int end) {
if(start<end) {
int middle = (start+end)/2;
myMergeSort(ars, start, middle);
myMergeSort(ars, middle+1, end);
merge(ars, start, middle, end);
}
}
public static void merge(int[] ars, int start, int middle, int end) {
int i=start, j=middle+1, k=0;
int[] temp = new int[end-start+1];
while(i<=middle && j<=end) {
temp[k++] = ars[i]<=ars[j] ? ars[i++]:ars[j++];
}
if(i<=middle && j>end) {
System.arraycopy(ars, i, ars, start+k, middle-i+1);
}
System.arraycopy(temp, 0, ars, start, k);
}
}