Submission #892788

#	Time	Username	Problem	Language	Result	Execution time	Memory
892788		ayalla	Feast (NOI19_feast)	C++14	100 / 100	176 ms	12356 KiB

feast

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define int long long int
#define pb push_back
#define pi pair<int, int>
#define pii pair<int, pi>
#define fir first
#define sec second
#define MAXN 300005
#define mod 998244353

int n, k;
int a[MAXN];

pi solve(int lambda)
{
  vector<int> dp(n + 1);
  vector<int> cnt(n + 1);
  dp[0] = 0;
  cnt[0] = 0;
  pi best = {0, 0};
  pi curr = {0, 0};
  auto f = [&](pi x)
  {
    return dp[x.fir] + x.sec;
  };
  for (int i = 1; i <= n; i++)
  {
    dp[i] = dp[i - 1];
    cnt[i] = cnt[i - 1];
    int id = i - 1;
    best.sec += a[id];
    if (f(best) < f({i - 1, a[id]}))
    {
      best = {i - 1, a[id]};
    }
    else if (f(best) == f({i - 1, a[id]}) && cnt[best.fir] > cnt[i - 1])
    {
      best = {i - 1, a[id]};
    }
    int s = dp[best.fir] + best.sec - lambda;
    if (s > dp[i])
    {
      dp[i] = s;
      cnt[i] = cnt[best.fir] + 1;
    }
  }
  return {dp[n], cnt[n]};
}
int aliens_trick()
{
  int l = 0, r = 1e15;
  while (l < r)
  {
    int mid = (l + r) >> 1;
    pi ans = solve(mid);
    (ans.sec > k) ? l = mid + 1 : r = mid;
  }
  pi ans = solve(l);
  return ans.fir + (l * k);
}
signed main()
{
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n >> k;
  for (int i = 0; i < n; i++)
    cin >> a[i];
  cout << aliens_trick() << endl;
  return 0;
}

Compilation message (stderr)

feast.cpp: In function 'std::pair<long long int, long long int> solve(long long int)':
feast.cpp:29:6: warning: variable 'curr' set but not used [-Wunused-but-set-variable]
   29 |   pi curr = {0, 0};
      |      ^~~~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29