#include <iostream>
using namespace std;
int arr[500];
void merge(int l[],int l_len,int r[],int r_len)
{
	int i=0,j=0,k=0;
	while(i<l_len && j<r_len)
	{
		if(l[i] <= r[j])
		{
			arr[k++]=l[i++];
		}
		else arr[k++]=r[j++];
	}
	while(i<l_len) arr[k++]=l[i++];
	while(j<r_len) arr[k++]=r[j++];
}
void merge_sort(int arr[],int len)
{
	int mid = 0;
	if(len<2) return;
	else mid = len/2;
	int l[mid+1] = {0};
	int r[len-mid+1] = {0};
	for(int i=0;i<mid;i++) l[i]=arr[i];
	for(int i=mid;i<len;i++) l[i-mid]=arr[i];
	merge_sort(l,mid);
	merge_sort(r,mid);
	merge(l,mid,r,len-mid);
}
int main()
{
	srand(time(NULL));
	int n = 50;
	cout<<n<<"\n";
	for(int i=0;i<n;i++) 
	{
		arr[i] = rand()%n + 1;
		cout<<arr[i]<<" ";
	}
	merge_sort(arr,n);
	return 0;
}

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