package 小米oj;

public class 歸併排序 {
	
	
public static void main(String[] args) {
	
	int a[]= {1,2,2,35,22,55,100,2,1000};
	use(a);
	for(int i = 0;i<a.length;i++)
	{
		System.out.println(a[i]);
	}
	
	
}

public static void use(int a[])
{
	merge(a,0,(a.length-1)/2,a.length-1);
}
public static void mergesort
 
(int a[],int start,int mid,int end)
{
	int temp[] = new int[end-start+2];
	int p=0;
	int i=start,j=mid+1;
	while(i<=mid&&j<=end)
	{
	if(a[i]<=a[j])
	{
		temp[p++] = a[i++];
		
	}
	else {
		temp[p++] = a[j++];
	}}
	while(i<=mid)
	{
		temp[p++] = a[i++];
	}
	while(j<=end)
	{
		temp[
 
p++] =a[j++];
	}
	p=0;
	for(int pp=start;pp<=end;pp++)
	{
		a[pp] = temp[p++];
	}
}
public static void merge(int a[],int start,int mid,int end)
{
	if(start+1!=end)
	{if(start!=end) {
		merge(a,start,(start+mid)/2,mid);
		merge(a,(mid+1),(mid+1+end)/2,end);}
	}
	mergesort(a,start,mid,end);
	
}

}