Why am I having a problem of run error while submitting the code

#include

using namespace std;

void merge(int arr[], int l, int m, int r)
{
int i, j, k;
int n1 = m - l + 1;
int n2 = r - m;

/* create temp arrays */
int L[n1], R[n2]; 

/* Copy data to temp arrays L[] and R[] */
for (i = 0; i < n1; i++) 
    L[i] = arr[l + i]; 
for (j = 0; j < n2; j++) 
    R[j] = arr[m + 1 + j]; 

/* Merge the temp arrays back into arr[l..r]*/
i = 0; // Initial index of first subarray 
j = 0; // Initial index of second subarray 
k = l; // Initial index of merged subarray 
while (i < n1 && j < n2) { 
    if (L[i] <= R[j]) { 
        arr[k] = L[i]; 
        i++; 
    } 
    else { 
        arr[k] = R[j]; 
        j++; 
    } 
    k++; 
} 

/* Copy the remaining elements of L[] */
while (i < n1) { 
    arr[k] = L[i]; 
    i++; 
    k++; 
} 

/* Copy the remaining elements of R[] */
while (j < n2) { 
    arr[k] = R[j]; 
    j++; 
    k++; 
} 

}

/* l is for left index and r is right index of the
sub-array of arr to be sorted */
void mergeSort(int arr[], int l, int r)
{
if (l < r) {
// Same as (l+r)/2, but avoids overflow for
// large l and h
int m = l + (r - l) / 2;

    // Sort first and second halves 
    mergeSort(arr, l, m); 
    mergeSort(arr, m + 1, r); 

    merge(arr, l, m, r); 
} 

}

void printArray(int A[], int size)
{
for (int i = 0; i < size; i++)
cout<<A[i]<<" ";

}

/* Driver program to test above functions */
int main()
{
int arr[100000];
int arr_size;

cin>>arr_size;

for(int i=0 ; i<arr_size ; i++)
{
	cin>>arr[i];
} 


mergeSort(arr, 0, arr_size - 1); 

printArray(arr, arr_size); 
return 0; 

}

Hello @amangupta,

You are not satisfying the constraints given in the question:
1<=N<=2*10^5
And the size of your array is 10^5.

Increase the size and it will work perfectly.
Hope, this would help.