TSORT : Runtime Error but work in Dev

#include
int ar[100000],b[100000];
void merging(int ar[],int start ,int mid,int end);
void merge(int ar[],int start,int end);
int main()

{
using namespace std;
int n;
cout<<"\n Enter total no of nos “;
cin>>n;
for(int i=0;i<n;i++)
cin>>ar[i];
merge(ar,0,n-1);
for(int i=0;i<n;i++)
{
if(i==0 || ar[i]!=ar[i-1])
cout<<ar[i]<<” ";
}
return 0;
}

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

void merging(int ar[],int start ,int mid,int end)
{

 int a=start,k=start, c=mid+1;
 while(a<=mid && c<=end)
 {
                  if(ar[a]<ar[c])
                    b[k++]=ar[a++];
                  else
                    b[k++]=ar[c++];
 }
 if(a>mid)
   while(c<=end) 
     b[k++]=ar[c++];
 else
   while(a<=mid) 
     b[k++]=ar[a++];
 for(a=start;a<=end;a++)
   ar[a]=b[a];

}

//