Question
Enter an array of length n and rank it in ascending order, ie for any adjacent two numbers a[i], a[i+1], a[i] <= a[i+1].
Sample
Input
The first line is an integer n indicating the length of the number
The next n lines, each line an integer a[i], represent the contents of the array.
Output
Output first behavior array length n
Next n acts as a result of sorting.
Result
链接: link.
图片:
Code of Shell Sort and Merge Sort
This is Shell Sort
// ShellSort
import java.util.Scanner;
class ShellSOrt {
public int[] Sort(int a[]) {
int len=a.length,gap=len/2,temp;
while(gap>0) {
for(int i=gap;i<len;i++) {
int j=i;
while(j>=gap&&a[j-gap]>a[j]) {
temp=a[j];
a[j]=a[j-gap];
a[j-gap]=temp;
j=j-gap;
}
}
gap=gap/2;
}
return a;
}
}
public class TestOfIt {
public static void main(String args[]) {
Scanner reader=new Scanner(System.in);
int num=reader.nextInt();
int a[]=new int[num];
for(int i=0;i<a.length;i++) {
a[i]=reader.nextInt();
}
ShellSOrt S1=new ShellSOrt();
int a1[]=S1.Sort(a);
System.out.println(num);
for(int j=0;j<a1.length;j++) {
System.out.println(a[j]);
}
}
}
The next one is Merge sort
import java.util.Scanner;
class MergeSort {
public void mergeSort(int []a) {
int[] workSpace=new int[a.length];
recMergeSort(a,workSpace,0,a.length-1);
}
private void recMergeSort(int []a,int []b,int low,int high) {
if(low==high)
return;
else {
int middle=(low+high)/2;
recMergeSort(a,b,low,middle);//左边排序
recMergeSort(a,b,middle+1,high);//右边排序
merge(a,b,low,middle+1,high);
}
}
private void merge(int a[],int workSpace[],int lowPtr,int highPtr,int higher) {
int j=0;
int lower=lowPtr;
int mid=highPtr-1;
int n=higher-lower+1;
while(lowPtr<=mid&&highPtr<=higher) {
if(a[lowPtr]<a[highPtr]) {
workSpace[j++]=a[lowPtr++];
}
else {
workSpace[j++]=a[highPtr++];
}
}while(lowPtr<=mid) {
workSpace[j++]=a[lowPtr++];
}
while(highPtr<=higher) {
workSpace[j++]=a[highPtr++];
}
for(j=0;j<n;j++) {
a[lower+j]=workSpace[j];
}
}
}
public class TestOfIt {
public static void main(String args[]) {
Scanner reader=new Scanner(System.in);
int num=reader.nextInt();
int a[]=new int[num];
for(int i=0;i<a.length;i++) {
a[i]=reader.nextInt();
}
ShellSOrt S1=new ShellSOrt();
int a1[]=S1.Sort(a);
System.out.println(num);
for(int j=0;j<a1.length;j++) {
System.out.println(a[j]);
}
}
}
public class TestOfIt {
public static void main(String args[]) {
Scanner reader=new Scanner(System.in);
int num=reader.nextInt();
int a[]=new int[num];
for(int i=0;i<a.length;i++) {
a[i]=reader.nextInt();
}
ShellSOrt S1=new ShellSOrt();
int a1[]=S1.Sort(a);
System.out.println(num);
for(int j=0;j<a1.length;j++) {
System.out.println(a[j]);
}
}
}
Summary
Shell sort is a sort which need a gap, exchange a[i] and a[i+gap],in general, the gap is a.length/2, after the first sort, gap need to be divided by 2 again till gap=0.divide to groups the number of group is length/2 in general.
Different from Shell sort. Merge sort adopts the idea of divide and conquer，the algorithm needs to divide an array till it is divided by many arrays which has only a number, and then, sort to new array.
The difference is Shell sort needs a gap,the number which need to sort depend on gap. However Merge sort just need to sort the numbers nearby.