#435873 (C++17) No.999 てん vs. ほむ

• 問題: No.999 てん vs. ほむ
• ユーザー: Haar
• 提出日時: 2020-02-28 21:34:46
• 言語: C++17 (gcc 13.2.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 31 ms / 2,000 ms
• コード長: 2,555 bytes
• コンパイル時間: 2,274 ms
• コンパイル使用メモリ: 198,700 KB
• 実行使用メモリ: 7,936 KB
• 最終ジャッジ日時: 2024-04-21 18:04:18
• 合計ジャッジ時間: 3,431 ms
• ジャッジサーバーID （参考情報）: judge4 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 6,812 KB
testcase_01	AC	1 ms; 6,944 KB
testcase_02	AC	2 ms; 6,944 KB
testcase_03	AC	2 ms; 6,944 KB
testcase_04	AC	2 ms; 6,944 KB
testcase_05	AC	2 ms; 6,944 KB
testcase_06	AC	2 ms; 6,940 KB
testcase_07	AC	2 ms; 6,940 KB
testcase_08	AC	3 ms; 6,940 KB
testcase_09	AC	28 ms; 7,552 KB
testcase_10	AC	10 ms; 6,940 KB
testcase_11	AC	7 ms; 6,940 KB
testcase_12	AC	13 ms; 6,940 KB
testcase_13	AC	31 ms; 7,936 KB
testcase_14	AC	31 ms; 7,936 KB
testcase_15	AC	31 ms; 7,936 KB
testcase_16	AC	30 ms; 7,936 KB
testcase_17	AC	22 ms; 7,552 KB
testcase_18	AC	21 ms; 7,552 KB
testcase_19	AC	22 ms; 7,552 KB
testcase_20	AC	22 ms; 7,680 KB
testcase_21	AC	31 ms; 7,808 KB
testcase_22	AC	30 ms; 7,680 KB

ソースコード

#include <bits/stdc++.h>

using i32 = int_fast32_t;
using i64 = int_fast64_t;
using u32 = uint_fast32_t;
using u64 = uint_fast64_t;
using f64 = double;
using f80 = long double;

#define FOR(v, a, b) for(i64 v = (a); v < (b); ++v)
#define FORE(v, a, b) for(i64 v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(i64 v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define fst first
#define snd second
#define UNIQ(v) (v).erase(unique(ALL(v)), (v).end())
#define bit(i) (1LL<<(i))

#ifdef DEBUG
#include <Mylib/Debug/debug.cpp>
#else
#define dump(...) ((void)0)
#endif

using namespace std;

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}
template <typename T> void puts_all(const T &value){std::cout << value << "\n";}
template <typename T, typename ...Args> void puts_all(const T &value, const Args&... args){std::cout << value << " ";puts_all(args...);}

template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}
template <typename T> auto make_vector(int n, int m, const T &value){return vector<vector<T>>(n, vector<T>(m, value));}


struct Init{
  Init(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(12);
    cerr << fixed << setprecision(12);
  }
}init;




int main(){
  int N;

  while(cin >> N){
    vector<i64> A(2*N); cin >> A;
    i64 S = accumulate(ALL(A), 0LL);

    vector<i64> even(N), odd(N);

    REP(i,N){
      even[i] = A[2*i];
      odd[i] = A[2*i+1];
    }

    dump(even, odd);

    i64 ans = accumulate(ALL(even), 0LL) - accumulate(ALL(odd), 0LL);

    vector<i64> even_sum(N+1), odd_sum(N+1);
    REP(i,N){
      even_sum[i+1] = even_sum[i] + even[i];
      odd_sum[i+1] = odd_sum[i] + odd[i];
    }
    
    REP(i,N){
      i64 t = even_sum[i] + odd_sum[N] - odd_sum[i];

      chmax(ans, 2 * t - S);
    }

    puts_all(ans);
  }

  return 0;
}