第三周作业——冒泡排序和归并排序

package d;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;

public class sort {
public static void main(String[] args) {
readFile    rf = new readFile();
bubbleSort  bs = new bubbleSort();
writFile    wf = new writFile();
mergeSort   ms = new mergeSort();

double starttime1 = System.currentTimeMillis();
wf.writFile(bs.bubbleSort(rf.readFile()),"largeW_bubble.txt");
double endtime1 = System.currentTimeMillis();
System.out.println("bubble sort time: " + (endtime1-starttime1) + "ms");

double starttime2 = System.currentTimeMillis();
wf.writFile(ms.mergeSort(rf.readFile(), 0, rf.readFile().length-1),"largeW_merge.txt");
double endtime2 = System.currentTimeMillis();
System.out.println("merge sort time: " + (endtime2-starttime2) + "ms");
}
}

/////////////////////////////////////////////////
class writFile {
public void writFile(int[] wArray,String srcfile){
int num = 0;
PrintWriter pw;
try {
pw = new PrintWriter(new File(srcfile));
while(wArray.length>num){
pw.printf("%d: %d\n", num+1,wArray[num]);
num++;
}
pw.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}

System.out.println("运行结束，一共有"+num+"个数据。");
}
}
/////////////////////////////////////////////////
class readFile{
public int[] readFile(){
int tempArray[] = new int[1000000],i=0;
Scanner myfile;
try {
myfile = new Scanner(new File("largeW.txt"));
while(myfile.hasNext()){
tempArray[i]=myfile.nextInt();
i++;
}
myfile.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return tempArray;
}
}
///////////////////////////////////////////////
class bubbleSort{
public int[] bubbleSort(int[] bubbleArray){
int temp;
//double start = System.currentTimeMillis();
for(int i=bubbleArray.length-1;i>0;i--){
for(int j=0;j<i;j++){
if(bubbleArray[j]>bubbleArray[j+1]){
temp=bubbleArray[j];
bubbleArray[j]=bubbleArray[j+1];
bubbleArray[j+1]=temp;
}
}
}
//double end = System.currentTimeMillis();
//System.out.println("time: " + (end-start) + "ms");
return bubbleArray;
}
}
//////////////////////////////////////////////////////////////
class  mergeSort{
public int[] mergeSort(int[] arrays,int start,int end){
if(start<end){
int m=(start+end)/2;
mergeSort(arrays,start,m);
mergeSort(arrays,m+1,end);
return combin_arrays(arrays,start,m,end);
}
return new int[0];
}

public int[] combin_arrays(int[] arrays,int start,int m,int end){
int length=end-start+1;
int temp[]=new int[length];
int i=start;
int j=m+1;
int c=0;
while(i<=m &&j<=end){
if(arrays[i]<arrays[j]){
temp[c++]=arrays[i++];
}else{
temp[c++]=arrays[j++];
}
}
while(i<=m){
temp[c++]=arrays[i++];
}
while(j<=end){
temp[c++]=arrays[j++];
}
c=0;
for(int t=start;t<=end;t++,c++){
arrays[t]=temp[c];
}
return arrays;
}
}