第三题 #include <iostream> using namespace std; int main() { long long T; cin >> T; while (T--) { long long n, l, r; cin >> n >> l >> r; long long needadd = 0; long long needmin = 0; long long canadd = 0; long long canmin = 0; for (long long i = 0; i < n; i++) { long long t; cin >> t; if (t < l) needadd += l - t; if (t > r) needmin += t - r; if (t > l) canmin += t - l; if (t < r) canadd += r - t; } // cout<<needadd<<" "<<canadd<<" "<<needmin<<" "<<canmin<<endl; if (needadd > canmin || needmin > canadd) cout << -1 << endl; else cout << max(needadd, needmin) << endl; } }