include

include

include

using namespace std;

struct Activity { int start; int finish; int index; // Original index of the activity };

bool compare(Activity a, Activity b) { return a.finish < b.finish; }

void maxActivities(vector& activities) { int n = activities.size(); // Sort activities based on finish time sort(activities.begin(), activities.end(), compare);

vector<int> selectedActivities;
selectedActivities.push_back(activities[0].index);
int prevFinish = activities[0].finish;

for (int i = 1; i < n; ++i) {
    if (activities[i].start >= prevFinish) {
        selectedActivities.push_back(activities[i].index);
        prevFinish = activities[i].finish;
    }
}

// Output
for (int i = 0; i < selectedActivities.size(); ++i) {
    cout << selectedActivities[i] << "\t";
}
cout << endl;

}

int main() { int n; cin >> n;

vector<Activity> activities(n);
for (int i = 0; i < n; ++i) {
    cin >> activities[i].start >> activities[i].finish;
    activities[i].index = i + 1; // Assign original index
}

maxActivities(activities);

return 0;

}****

My typescript solution:

let maxCount = 0;
    let lastTwo = [[0,0],[0,0]];
    intervals.sort((a,b) => a[1]-b[1]);
    intervals.forEach((interval) => {
        if(interval[0] > lastTwo[1][1]) {
            maxCount++;
            lastTwo[1] = interval;
        } else if (interval[0] > lastTwo[0][1]) {
            maxCount++;
            lastTwo[0] = interval
            lastTwo.sort((a,b) => a[1]-b[1])
        }
    })
    return maxCount;

Here is my solution in java, javascript, python, C, C++, Csharp HackerRank Interval Selection Problem Solution

Here is Interval Selection problem solution - https://programs.programmingoneonone.com/2021/07/hackerrank-interval-selection-problem-solution.html

I understand the question after a good 15 minutes of reading. Not Google interview worthy problem solving skills yet, but I'm proud of myself for getting this far.