kickstart C

bool cmp(array<ll, 3> a, array<ll, 3> b){
    return a[1] < b[1];
}

void solve(){
    ll D = in;
    int n = in;
    ll X = in;
    vector<array<ll, 3>> seeds;
    vector<ll> srt;
    for(int i = 0; i<n; i++){
        ll a = in, b = in, c = in;
        //amount
        //length
        //value
        seeds.pb({a, b, c});
        srt.pb(b);
    }
    srt.pb(D);
    sort(all(seeds), cmp);
    sort(all(srt));
    srt.resize(unique(all(srt)) - srt.begin());
    ll last = 0;
    priority_queue<pair<ll, ll>> pq; //value, amount
    int ptr = 0;
    ll ans = 0;
    for(ll x : srt){
        ll tim = x - last;
        ll poss = tim * X;
        while(poss > 0 && sz(pq)){
            auto [v, c] = pq.top(); pq.pop();
            ll delta = min(c, poss);
            poss -= delta;
            c -= delta;
            ans += v * delta;
            cerr << delta << " " << v << "\n";
            if(c){
                pq.push(mp(v, c));
            }
        }
        last = x;
        while(ptr < sz(seeds) && seeds[ptr][1] <= x){
            pq.push(mp(seeds[ptr][2], seeds[ptr][0]));
            ptr++;
        }
    }
    cout << ans << "\n";
}