Process terminated with status -1073741571 closest pair algorithm with million points

Question

I have to make a program to randomly generate 1000000 points and get the shortest distance using brute force and divide and conquer. When I use values < 100,000 it works fine for divide and conquer, but above that it gives me that error. Here is the code and some comments. The brute force stops working after around 10k points.

#include <iostream>
#include <cfloat>
#include <cstdlib>
#include <cmath>
#include <stdlib.h>
#include <time.h>
using namespace std;

/*
 * Point Declaration
 */
struct Point
{
    int x, y;
};

/*
 * sort array of points according to X coordinate
 */
int compareX(const void* a, const void* b)
{
    Point *p1 = (Point *)a, *p2 = (Point *)b;
    return (p1->x - p2->x);
}
/*
 * sort array of points according to Y coordinate
 */
int compareY(const void* a, const void* b)
{
    Point *p1 = (Point *)a, *p2 = (Point *)b;
    return (p1->y - p2->y);
}
/*
 * find the distance between two points
 */
float dist(Point p1, Point p2)
{
    return sqrt((p1.x - p2.x) * (p1.x - p2.x) + (p1.y - p2.y) * (p1.y - p2.y));
}
/*
 * return the smallest distance between two points
 */
float small_dist(Point P[], int n)
{
    float min = FLT_MAX;
    for (int i = 0; i < n; ++i)
    {
        for (int j = i + 1; j < n; ++j)
        {
            if (dist(P[i], P[j]) < min)
                min = dist(P[i], P[j]);
        }
    }
    return min;
}
/*
 * find the distance beween the closest points of strip of given size
 */
float stripClosest(Point strip[], int size, float d)
{
    float min = d;
    for (int i = 0; i < size; ++i)
    {
        for (int j = i + 1; j < size && (strip[j].y - strip[i].y) < min; ++j)
        {
            if (dist(strip[i],strip[j]) < min)
                min = dist(strip[i], strip[j]);
        }
    }
    return min;
}
/*
 * find the smallest distance.
 */
float closestUtil(Point Px[], Point Py[], int n)
{
    if (n <= 3)
        return small_dist(Px, n);
    int mid = n / 2;
    Point midPoint = Px[mid];
    Point Pyl[mid + 1];
    Point Pyr[n - mid - 1];
    int li = 0, ri = 0;
    for (int i = 0; i < n; i++)
    {
        if (Py[i].x <= midPoint.x)
            Pyl[li++] = Py[i];
        else
            Pyr[ri++] = Py[i];
    }
    float dl = closestUtil(Px, Pyl, mid);
    float dr = closestUtil(Px + mid, Pyr, n-mid);
    float d = min(dl, dr);
    Point strip[n];
    int j = 0;
    for (int i = 0; i < n; i++)
    {
        if (abs(Py[i].x - midPoint.x) < d)
            strip[j] = Py[i], j++;
    }
    return min(d, stripClosest(strip, j, d));
}
/*
 * finds the smallest distance
 */
float closest(Point P[], int n)
{
    Point Px[n];
    Point Py[n];
    for (int i = 0; i < n; i++)
    {
        Px[i] = P[i];
        Py[i] = P[i];
    }
    qsort(Px, n, sizeof(Point), compareX);
    qsort(Py, n, sizeof(Point), compareY);
    return closestUtil(Px, Py, n);
}

void randomPoints(int n, Point P[]){
    for(int i=0; i<n; i++){
        P[i].x = rand();
        P[i].y = rand();
    }
}

void printPoints(int n, Point P[]){
    for(int i=0; i<n; i++){
        cout << "(" << P[i].x << ", " << P[i].y << ")";
        cout << endl;
    }
}

void distanceAll(int n, Point P[]){
    for(int i=0; i<n-1; i++){
        for(int j=i+1; j<n; j++){
            cout << dist(P[i], P[j]) << endl;
        }
    }
}

/*
 * Main
 */
int main()
{
    srand (time(NULL));
    int n;
    cout << "How many points do you want? ";
    cin >> n;
    Point *P = new Point[n];
    randomPoints(n, P);

    // Driver Function
    int option;

    cout << "1. Display all points generated.\n";
    cout << "2. Display distance between all possible points.\n";
    cout << "3. Distance between closest pair of points (brute force).\n";
    cout << "4. Distance between closest pair of points (divide & conquer).\n";

    cout << "Enter an option (-1 to exit): ";
    cin >> option;

    // Validation
    while(option != -1){
        if(option == 1){
            printPoints(n, P);
        }
        else if(option == 2){
            distanceAll(n, P);
            cout << endl;
        }
        else if(option == 3){
            cout << "The closest distance (divide & conquer) is: " << small_dist(P, n) << endl;
        }
        else if(option == 4){
            cout << "The closest distance (divide & conquer) is: " << closest(P, n) << endl;
        }
        else{
            cout << "Please enter a valid option: ";
            cin >> option;
        }
        cout << "\n1. Display all points generated.\n";
        cout << "2. Display distance between all possible points.\n";
        cout << "3. Distance between closest pair of points (brute force).\n";
        cout << "4. Distance between closest pair of points (divide & conquer).\n";
        cout << "Enter an option (-1 to exit): ";
        cin >> option;
        cout << endl;
    }

    return 0;
}