Java：插入排序和归并排序

插入排序

import java.util.Scanner;

public class Insertsort {
	public static int[] randomarray(int len,int max) {
		int[] arr=new int[len];
		for(int i=0;i<len;i++)
		{
			arr[i]=(int)(Math.random()*max);
		}
		return arr;
	}
	public static void main(String[] args) {
		Scanner scan=new Scanner(System.in);
		System.out.printf("请输入随机数组的长度：");
		int len=scan.nextInt();
		System.out.printf("请输入随机数组的数字最大值：");
		int max=scan.nextInt();
		int[] arr=randomarray(len,max);
		System.out.printf("生成的随机数组为：");
		for(int k=0;k<len;k++)
		{
			System.out.printf("%d ",arr[k]);
			if(k==len-1) System.out.println();
		}
		System.out.printf("排序过程：\n");
		for(int i=0;i<len;i++)
		{
			for(int j=i;j>0;j--)
			{
				if(arr[j]<arr[j-1])
				{
					int t;
					t=arr[j];
					arr[j]=arr[j-1];
					arr[j-1]=t;
				}
			}
			for(int k=0;k<len;k++)
			{
				System.out.printf("%d ",arr[k]);
				if(k==len-1) System.out.println();
			}
		}
		scan.close();
	}
}

归并排序

import java.util.Scanner;

public class Mergesort {
	static int n;
	public static int[] randomarray(int len,int max) {
		int[] arr=new int[len];
		for(int i=0;i<len;i++)
		{
			arr[i]=(int)(Math.random()*max);
		}
		return arr;
	}
	public static void merge(int[] r,int[] r1,int low,int mid,int high) {
		int i=low,j=mid+1,k=low;
		while((i<=mid)&&(j<=high))
		{
			if(r[i]<=r[j]) r1[k++]=r[i++];
			else r1[k++]=r[j++];
		}
		while(i<=mid) r1[k++]=r[i++];
		while(j<=high) r1[k++]=r[j++];
	}
	public static void mergepass(int[] r,int[] r1,int len) {
		int i=0,j;
		while(i+2*len-1<n)
		{
			merge(r,r1,i,i+len-1,i+2*len-1);
			i=i+2*len;
		}
		if((i+len-1)<n-1) merge(r,r1,i,i+len-1,n-1);
		else for(j=i;j<n;j++) r1[j]=r[j];
	}
	public static void mergesort(int[] r) {
		int len=1;
		int[] r1=new int[n];
		while(len<n)
		{
			mergepass(r,r1,len);
			len=len*2;
			mergepass(r1,r,len);
			len=len*2;
		}
		System.out.printf("排序结果：");
		for(int k=0;k<n;k++)
		{
			System.out.printf("%d ",r[k]);
			if(k==len-1) System.out.println();
		}
	}
	public static void main(String[] args) {
		Scanner scan=new Scanner(System.in);
		System.out.printf("请输入随机数组的长度：");
		n=scan.nextInt();
		System.out.printf("请输入随机数组的数字最大值：");
		int max=scan.nextInt();
		int[] arr=randomarray(n,max);
		System.out.printf("生成的随机数组为：");
		for(int k=0;k<n;k++)
		{
			System.out.printf("%d ",arr[k]);
			if(k==n-1) System.out.println();
		}
		mergesort(arr);
		scan.close();
	}
}