[CSES] High Score

void solve() {
    ll n, m;
    cin >> n >> m;

    vector<vpll> v(n);
    rep(i, m) {
        ll x, y, w;
        cin >> x >> y >> w;
        --x, --y;
        v[x].pb({ y, -w });
    }

    vll d(n, inf);
    d[0] = 0;
    rep(i, n) {
        rep(j, n) {
            for (auto& child : v[j]) {
                if (d[j] < inf && d[child.f] > d[j] + child.s) {
                    d[child.f] = max(-inf, d[j] + child.s);
                }
            }
        }
    }

    rep(i, n) {
        rep(j, n) {
            for (auto& child : v[j]) {
                if (d[j] < inf && d[child.f] > d[j] + child.s) {
                    d[child.f] = -inf;
                }
            }
        }
    }

    if (d[n - 1] == -inf) cout << -1 << "\n";
    else cout << -d[n - 1] << "\n";
}