Submission #216933

#	Time	Username	Problem	Language	Result	Execution time	Memory
216933		quocnguyen1012	Cover (COCI18_cover)	C++14	120 / 120	8 ms	512 KiB

cover

#include <bits/stdc++.h>

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back

using namespace std;
typedef long long ll;
typedef pair<int, int> ii;

const int maxn = 5005;

ll f[maxn];
int N;
ii p[maxn];

signed main(void)
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #ifdef LOCAL
    freopen("A.INP", "r", stdin);
    freopen("A.OUT", "w", stdout);
  #endif // LOCAL
  cin >> N;
  for(int i = 1; i <= N; ++i){
    cin >> p[i].fi >> p[i].se;
    p[i].fi = abs(p[i].fi);
    p[i].se = abs(p[i].se);
  }
  sort(p + 1, p + 1 + N);
  vector<int> st;
  for(int i = 1; i <= N; ++i){
    while(st.size() && p[st.back()].se <= p[i].se)
      st.pop_back();
    st.eb(i);
  }
  int n = st.size();
  for(int i = 1; i <= n; ++i){
    f[i] = 1e18;
    for(int j = 1; j <= i; ++j){
      f[i] = min(f[i], f[j - 1] + 1ll * p[st[i - 1]].fi * p[st[j - 1]].se);
    }
  }
  cout << 4ll * f[n];
}

• Subtask 1: 120 / 120