Submission #836262

#	Time	Username	Problem	Language	Result	Execution time	Memory
836262		Johann	Meetings (IOI18_meetings)	C++14	17 / 100	85 ms	8556 KiB

meetings

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

typedef long long ll;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef pair<ll, ll> pii;
typedef vector<pii> vpii;
typedef vector<vpii> vvpii;
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()

const ll INF = 1LL << 60;

struct item
{
  int l, r, m;
  void set(int i) { l = r = m = i; }
};
struct segtree
{
  vector<item> arr;
  int size;
  const item NEUTRAL = {0, 0, 0};
  item combine(const item &a, const item &b, int len)
  {
    return {(a.l == len) ? a.l + b.l : a.l, (b.r == len) ? b.r + a.r : b.r, max(a.r + b.l, max(a.m, b.m))};
  }
  void init(vector<int> &H)
  {
    size = 1;
    while (size < sz(H))
      size *= 2;
    arr.resize(2 * size);
    for (int i = 0; i < sz(H); ++i)
      set(i, (H[i] == 1));
  }
  void set(int i, int v) { set(i, v, 1, 0, size); }
  void set(int i, int v, int x, int lx, int rx)
  {
    if (rx - lx == 1)
    {
      arr[x].set(v);
      return;
    }
    int m = (lx + rx) / 2;
    if (i < m)
      set(i, v, 2 * x, lx, m);
    else
      set(i, v, 2 * x + 1, m, rx);
    arr[x] = combine(arr[2 * x], arr[2 * x + 1], (rx - lx) / 2);
  }
  int query(int l, int r) { return query(l, r, 1, 0, size).m; }
  item query(int l, int r, int x, int lx, int rx)
  {
    if (l <= lx && rx <= r)
      return arr[x];
    if (r <= lx || rx <= l)
      return NEUTRAL;
    int m = (lx + rx) / 2;
    item a = query(l, r, 2 * x, lx, m);
    item b = query(l, r, 2 * x + 1, m, rx);
    return combine(a, b, (rx - lx) / 2);
  }
};
segtree seg;

vi minimum_costs(std::vector<int> H, std::vector<int> L,
                 std::vector<int> R)
{
  int N = sz(H);
  int Q = L.size();
  seg.init(H);
  vi ans(Q);
  for (int j = 0; j < Q; ++j)
  {
    ans[j] = 2 * (R[j] - L[j] + 1) - seg.query(L[j], R[j] + 1);
  }
  return ans;
}

Compilation message (stderr)

meetings.cpp: In function 'vi minimum_costs(std::vector<int>, std::vector<int>, std::vector<int>)':
meetings.cpp:72:7: warning: unused variable 'N' [-Wunused-variable]
   72 |   int N = sz(H);
      |       ^

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