My solution:

include

using namespace std;

//Define the structs Workshops and Available_Workshops. struct Workshop { int st; int dur; int et; };

struct Available_Workshops { int n; vector wsarr; };

//Implement the functions initialize and CalculateMaxWorkshops Available_Workshops* initialize(int start_time[], int duration[], int n) { Available_Workshops *ws_avail = new Available_Workshops;

ws_avail->n = n;

for(int i=0; i < n; i++)
{
    Workshop ws = {start_time[i], duration[i], start_time[i] + duration[i]};
    ws_avail->wsarr.push_back(ws);
}

return ws_avail;

}

int CalculateMaxWorkshops(Available_Workshops* ws_avail) { int cnt = 1; int cur; vector vec;

sort(ws_avail->wsarr.begin(), ws_avail->wsarr.end(), [](const Workshop &w1, const Workshop &w2){return w1.et < w2.et;});

cur = ws_avail->wsarr[0].et;

for(int j=0; j<(ws_avail->n - 1); j++)
{
    if(cur <=  ws_avail->wsarr[j+1].st)
    {
        cnt++;
        cur = ws_avail->wsarr[j+1].et;  
    }
}

return cnt;

}

int main(int argc, char argv[]) { int n; // number of workshops cin >> n; // create arrays of unknown size n int start_time = new int[n]; int* duration = new int[n];

for(int i=0; i < n; i++){
    cin >> start_time[i];
}
for(int i = 0; i < n; i++){
    cin >> duration[i];
}

Available_Workshops * ptr;
ptr = initialize(start_time,duration, n);
cout << CalculateMaxWorkshops(ptr) << endl;
return 0;

}