Submission #778213

#	Time	Username	Problem	Language	Result	Execution time	Memory
778213		NeroZein	Meetings (IOI18_meetings)	C++17	0 / 100	21 ms	2372 KiB

meetings

#include "meetings.h"
#include "bits/stdc++.h"
using namespace std; 

vector<int> seg;

void build (int nd, int l, int r, const vector<int>& a) {
  if (l == r) {
    seg[nd] = a[l];
    return;
  }
  int mid = (l + r) >> 1;
  int rs = nd + ((mid - l + 1) << 1);
  build(nd + 1, l, mid, a);
  build(rs, mid + 1, r, a);
  seg[nd] = max(seg[nd + 1], seg[rs]); 
}

int qry (int nd, int l, int r, int s, int e) {
  if (l >= s && r <= e) {
    return seg[nd];
  }
  int mid = (l + r) >> 1;
  int rs = nd + ((mid - l + 1) << 1);
  if (mid >= e) {
    return qry(nd + 1, l, mid, s, e);
  } else {
    if (mid < s) {
      return qry(rs, mid + 1, r, s, e); 
    } else {
      return max(qry(nd + 1, l, mid, s, e), qry(rs, mid + 1, r, s, e));
    }
  }
}

std::vector<long long> minimum_costs(std::vector<int> H, std::vector<int> L,
                                     std::vector<int> R) {
  int n = (int) H.size();
  int q = L.size();
  stack<int> stk;
  vector<int> la(n);
  seg.resize(2 * n - 1); 
  for (int i = 0; i < n; ++i) {
    while (!stk.empty() && H[stk.top()] <= H[i]) {
      stk.pop();
    }
    la[i] = (stk.empty() ? -1 : stk.top());
    stk.push(i); 
  }
  while (stk.size()) stk.pop();
  vector<int> nx(n);
  for (int i = n - 1; i >= 0; --i) {
    while (!stk.empty() && H[stk.top()] <= H[i]) {
      stk.pop();
    }
    nx[i] = (stk.empty() ? n : stk.top());
    stk.push(i); 
  }
  vector<int> rng(n); 
  for (int i = 0; i < n; ++i) {
    if (H[i] == 1) {
      //cout << i << ' ' << la[i] << ' ' << nx[i] << '\n'; 
      rng[i] = nx[i] - la[i] - 1;      
    }
  }
  build(0, 0, n - 1, rng); 
  vector<long long> ans(q); 
  for (int i = 0; i < q; ++i) {
    int x = qry(0, 0, n - 1, L[i], R[i]); 
    //cout << "X: " << x << '\n'; 
    ans[i] = x + (R[i] - L[i] + 1 - x) * 2; 
  }
  return ans;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 15
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 40