#include <iostream>
using namespace std;

void merge(int start,int mid,int end,int arr[])
{
	int i,j,k;
	int len1=mid-start+1;
	int len2=end-mid;
	int left[len1],right[len2];
	for(k=0;k<len1;k++)
		left[k]=arr[start+k];
	for(k=0;k<len2;k++)
		right[k]=arr[mid+1+k];
	k=start;
	i=j=0;
	while(i<len1 && j<len2)
	{
		if(left[i]<right[j])
			arr[k++]=left[i++];
		else
			arr[k++]=right[j++];
	}
	
	while(i<len1)
		arr[k++]=left[i++];
	while(j<len2)
		arr[k++]=right[j++];
	
	
}

void sort(int start,int end,int arr[])
{
	int mid;
	if(start<end)
	{
		mid=(start+end)/2;
		sort(start,mid,arr);
		sort(mid+1,end,arr);
		merge(start,mid,end,arr);
	}
	
}

void mergeSort(int arr[],int len)
{
	sort(0,len-1,arr);
}

int main(int argc, char* argv[])
{
	int arr[]={5,4,3,2};
	int len=4;
	mergeSort(arr,len);
	for(int i=0;i<len;i++)
		cout<<arr[i]<<" ";
	cout<<endl;
	return 0;
}