Getting segmentation fault while using call by reference to return multiple values in recursive function

The question is to find the maximum and minimum element in an array and return their difference. I referred to the editorial of the problem on GeeksforGeeks. I used the tournament method, in which we partition any array having more than two elements into 2 parts, and find the maximum and minimum of those two arrays, and then return the answer after comparing these final values. The official solution listed here , uses a struct pair. I wanted to do it using call by reference values.

Initially I tried to return 2 values with the function like:

int r1,r2= Sample(a,high,low)

That is wrong(as we can return only 1 value from the function)
So I tried passing by reference like this:

void halfarrsol(int arr[], int low, int high, int &mi, int &ma){
int mid, min,max;
if(low==high){
    mi=ma=arr[low];
}
if(high==low+1){
    mi=arr[low], ma=arr[high];
    if(arr[low]>arr[high]){
        mi=arr[high];
        ma=arr[low];
    }
}
else {
    mid=(low+high)/2;
    halfarrsol(arr, low,mid,mi,ma);
    int minl=mi, maxl=ma;
    halfarrsol(arr, mid+1,high,mi,ma);
    int minr=mi, maxr=ma, fin=minl;
    if(minl>minr){
        fin= minr;
    }
    int fax=maxl;
    if(maxl<maxr){
        fax=maxr;
    }
    mi= fin;
    ma=fax;
}
}

The idea is that when I call the function, the final value of min and max (mi and ma) will be available.
One obvious error that I think might be messing things up is the

halfarrsol(arr, low,mid,mi,ma);
      int minl=mi, maxl=ma;

What I'm trying to here is store the obtained mi and ma vales(for this half array) in 'minl' and 'maxl' variables. Is this valid?
The overall code gives a segmentation error, and timeout: the monitored command dumped core error.
I'm not sure what exactly I'm messing up, or if this approach is completely wrong. I wanted to be able to solve this question without using a Struct Pair, and without using another class and creating an object.
There are also solutions like using a Tuple to store min and max values, but I considered them to be more applicable for when we have many return values, as here I am using 2 values only.
Is there any way to solve this problem recursively using call by reference?
If required you can view the driver code here

The bug is not easy to figure out if you are focused on logic. Your logic is more or less correct, issue is that when low == high, then it will call function recursively for indefinite times since you are not returning neither you have used else if for high == low + 1. Change to following:

...
if(low==high){
    mi=ma=arr[low];
}
else if(high==low+1){
    mi=arr[low], ma=arr[high];
    if(arr[low]>arr[high]){
        mi=arr[high];
        ma=arr[low];
    }
}
else {
...

Your recursion never stops. You forgot to end it in the very first case:

if(low==high){
    mi=ma=arr[low];
}

It then enters the second if, where the condition is false, and then goes to the else...

At least change to:

if(low==high){
    mi=ma=arr[low];
    return
}

Aside, the min/max can be computed more easily:

mid=(low+high)/2;
halfarrsol(arr, low, mid, mi, ma); // get min/max
int minr, maxr;
halfarrsol(arr, mid+1, high, minr, maxr); // get right min/max
if (mi>minr){ // correct min if needed
    mi = minr;
}
if (ma<maxr){ // correct max if needed
    ma=maxr;
}