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  1. #include <bits/stdc++.h>
  2. #define S second
  3. #define TT int T;cin >> T;while(T--)
  4. #define F first
  5. #define ll long long
  6. #define ld long double
  7. #define ue(times ,x) for(int _i = 0; _i < times; _i++){int _u, _v;cin >> _u >> _v;x[_u].push_back(_v);x[_v].push_back(_u);}
  8. #define de(times ,x) for(int _i = 0; _i < times; _i++){int _u, _v;cin >> _u >> _v;x[_u].push_back(_v);}
  9. #define pb push_back
  10. #define SRT(v) sort(v.begin(), v.end())
  11. #define SRT1(v) sort(v.begin()+1, v.end())
  12. #define TLE ios_base::sync_with_stdio(false);cin.tie(NULL)
  13. #define All(v) v.begin(),v.end()
  14. #define INF 223372036854775807
  15. typedef __int128 lll;
  16. using namespace std;
  17. const ll MAXN = 1e5+5;
  18. ll MOD = 1000000007;
  19.  
  20. ll fast_pow(ll base, ll exp, ll mod = MOD) {
  21. ll res = 1; base %= mod;
  22. while (exp > 0) {
  23. if (exp & 1) res = (ll)((__int128)res * base % mod);
  24. base = (ll)((__int128)base * base % mod);
  25. exp >>= 1;
  26. }
  27. return res;
  28. }
  29.  
  30. int main()
  31. {
  32. TLE;
  33. int t ; cin >> t;
  34. for (int g = 1; g <= t ; g++)
  35. {
  36. ll n; cin >> n;
  37. ll sum = 0 ;
  38. for ( int i = 1; i <= n; i++ ){
  39. ll x; cin >> x;
  40. sum = (sum + x) % MOD ;
  41. }
  42. ll ans = sum * fast_pow(2,n-1) % MOD ;
  43. cout << "Case " << g << ": " << ans << '\n';
  44. }
  45. return 0;
  46. }
Success #stdin #stdout 0.01s 5288KB
stdin
2
3
1 2 3
3
4 1 2
stdout
Case 1: 24
Case 2: 28