Merge Sort

#include <stdio.h>
#include <iostream>


using namespace std;

int arr[100000];

void merge(int lw,int mid,int hi)
{
	
    int L[mid-lw+1];
    int R[hi-mid+1];
    int tmp;
    
    for(int i=0;i<mid-lw+1;i++)
        L[i]=arr[lw+i];
    for(int i=0;i<hi-(mid+1)-1;i++)
        R[i]=arr[mid+i+1];
    
    int i = 0;
    int j = 0;
    int k = lw;
    
    while(i<(mid-lw+1) && j<(hi-mid))
    {
        if(L[i]<=R[j])
        {
            arr[k]=L[i];
            i++;
            k++;
        }
        else if(L[i]>R[j])
        {
            arr[k]=R[j];
            k++;
            j++;
        }
    }
    
    while(i<(mid-lw+1))
    {
        arr[k++]=L[i++];
    }
    while(j<(hi-mid))
    {
        arr[k++]=R[j++];
    }
}

void mergesort(int lw,int hi)
{
    if(hi>lw)
    {
        int mid=lw+(hi-lw)/2;
        mergesort(lw,mid);
        mergesort(mid+1,hi);
        merge(lw,mid,hi);
    }
}

int main() 
{
    int t,n;
	scanf("%d",&t);
	while(t--)
	{
	    scanf("%d",&n);
	    for(int i=0;i<n;i++)
	        scanf("%d",&arr[i]);
	    mergesort(0,n-1);
	    for(int i=0;i<n;i++)
	    	cout<<arr[i]<<" ";
	}
	return 0;
}