第三周作业——冒泡排序和归并排序

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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) {readFilerf = new readFile();bubbleSortbs = new bubbleSort();writFilewf = new writFile();mergeSortms = new mergeSort();double starttime1 = System.currentTimeMillis();//开始时间wf.writFile(bs.bubbleSort(rf.readFile()),"largeW_bubble.txt");//选择排序的运行double endtime1 = System.currentTimeMillis();//结束时间System.out.println("bubble sort time: " + (endtime1-starttime1) + "ms");//显示排序时间double starttime2 = System.currentTimeMillis();//开始时间wf.writFile(ms.mergeSort(rf.readFile(), 0, rf.readFile().length-1),"largeW_merge.txt");double endtime2 = System.currentTimeMillis();//结束时间System.out.println("merge sort time: " + (endtime2-starttime2) + "ms");//显示排序时间}}/////////////////////////////////////////////////class writFile {//写入文件public void writFile(int[] wArray,String srcfile){int num = 0;PrintWriter pw;try {pw = new PrintWriter(new File(srcfile));while(wArray.length>num){//写数组到文件pw.printf("%d: %d\n", num+1,wArray[num]);//写入文件格式num++;}pw.close();} catch (FileNotFoundException e) {e.printStackTrace();}System.out.println("运行结束，一共有"+num+"个数据。");}}/////////////////////////////////////////////////class readFile{//读取文件public int[] readFile(){int tempArray[] = new int[1000000],i=0;Scanner myfile;try {myfile = new Scanner(new File("largeW.txt"));while(myfile.hasNext()){//读取文件到数组tempArray[i]=myfile.nextInt();i++;} myfile.close();} catch (FileNotFoundException e) {e.printStackTrace();}return tempArray;}}///////////////////////////////////////////////class bubbleSort{//冒泡排序public int[] bubbleSort(int[] bubbleArray){int temp;//double start = System.currentTimeMillis();//开始时间for(int i=bubbleArray.length-1;i>0;i--){//排序操作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();//结束时间//System.out.println("time: " + (end-start) + "ms");//显示排序时间return bubbleArray;}}//////////////////////////////////////////////////////////////class  mergeSort{//合并排序    public int[] mergeSort(int[] arrays,int start,int end){//递归分成小部分        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){//合并数组        int length=end-start+1;        int temp[]=new int[length];//用来存放比较的数组，用完复制回到原来的数组        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;    }}
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