Submission #1119897

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119897		Hduong	Art Exhibition (JOI18_art)	C++17	50 / 100	164 ms	26148 KiB

art

#include <bits/stdc++.h>
#define INF 1e18
#define task "task"

using namespace std;
const int N = 5e5 + 5,
          M = 20;
long long a[N], b[N], n, x[M], res = 0, sum[N];
pair <long long, long long> pi[N];

void check() {
  long long sum = 0, mi = INF, ma = -INF, ok = 0;
  for (int i = 1; i <= n; i++) {
    if (x[i] == 0) continue ;
    sum += b[i];
    mi = min(mi, a[i]);
    ma = max(ma, a[i]);
    ++ok;
  }
  if (ok < 1) return ;
  res = max(res, sum - ma + mi);
}

void duyet(long long i) {
  if (i > n) check();
  else {
    for (int j = 0; j < 2; j++) {
      x[i] = j;
      duyet(i + 1);
    }
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  if (fopen (task".inp", "r")) {
    freopen (task".inp", "r", stdin);
    freopen (task".out", "w", stdout);
  }

  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i] >> b[i];
    pi[i].first = a[i];
    pi[i].second = b[i];
  }
  if (n <= 20) {
    duyet(1);
    cout << res;
  }
  else if (n <= 5000) {
    long long res = 0;
    sort(pi + 1, pi + n + 1);
    for(int i = 1; i <= n; i++) sum[i] = sum[i - 1] + pi[i].second;
    for (int l = 1; l < n; l++) {
      for (int r = l + 1; r <= n; r++) {
        res = max(res, sum[r] - sum[l - 1] - pi[r].first + pi[l].first);
      }
    }
    cout << res << "\n";
  }
  else {
    sort(pi + 1, pi + n + 1);
    for (int i = 1; i <= n; i++) sum[i] = sum[i - 1] + pi[i].second;
//    for (int i = 1; i <= n; i++) cout << pi[i].first << " " << pi[i].second << " " << sum[i] << "\n";
//    cout << "\n";
    long long res = sum[1], ma = pi[1].first;
    for (int i = 2; i <= n; i++) {
//      cout << ma << " " << res << " " << sum[i] - pi[i].first + ma << " " << sum[i] << " " << pi[i].first << "\n";
      res = max(res, sum[i] - pi[i].first + ma);
      ma = min(ma, sum[i - 1] + pi[i].first);
    }
    cout << res;
  }

  /// sum[r]  - a[max] - (sum[l - 1] - a[min])
}

Compilation message (stderr)

art.cpp: In function 'int main()':
art.cpp:39:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |     freopen (task".inp", "r", stdin);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
art.cpp:40:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |     freopen (task".out", "w", stdout);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 50