Merge Intervalsmedium

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

vector<vector<int>> merge(vector<vector<int>>& intervals) {
    // TODO: sort by start, then merge overlapping intervals
    return {};
}

int main() {
    vector<vector<int>> a = {{1,3},{2,6},{8,10},{15,18}};
    auto result = merge(a);
    for (auto& v : result)
        cout << "[" << v[0] << "," << v[1] << "] ";
    cout << endl;
    return 0;
}