Submission #654518

#	Time	Username	Problem	Language	Result	Execution time	Memory
654518		ayalla	Divide and conquer (IZhO14_divide)	C++14	100 / 100	52 ms	10780 KiB

divide

#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 endl '\n'
#define pb push_back
#define pi pair<int, int>
#define pii pair<int, pi>
#define fir first
#define sec second
#define MAXN 100005
#define mod 1000000007

struct item
{
  int pref, sum;
};

vector<item> seg;
vector<int> aux;

item single(int x)
{
  return {x, x};
}
item neutral()
{
  return {0, 0};
}
item merge(item a, item b)
{
  item ret;
  ret.pref = max(a.pref, a.sum + b.pref);
  ret.sum = a.sum + b.sum;
  return ret;
}
void update(int i, int l, int r, int q, int x)
{
  if (l == r)
  {
    seg[i] = single(x);
    return;
  }
  int mid = (l + r) >> 1;
  if (q <= mid)
    update(i << 1, l, mid, q, x);
  else
    update((i << 1) | 1, mid + 1, r, q, x);
  seg[i] = merge(seg[i << 1], seg[(i << 1) | 1]);
}
int query(int l, int r, int i, int x)
{
  if (l == r)
    return l;
  int mid = (l + r) >> 1;
  int curr = seg[i << 1].sum + seg[(i << 1) | 1].pref;
  if (curr >= x)
    return query(mid + 1, r, (i << 1) | 1, x - seg[i << 1].sum);
  if (seg[i << 1].pref < x)
    return -1;
  return query(l, mid, (i << 1), x);
}
void build(int l, int r, int i)
{
  if (l == r)
  {
    seg[i] = single(aux[l]);
    return;
  }
  int mid = (l + r) >> 1;
  build(l, mid, i << 1);
  build(mid + 1, r, (i << 1) | 1);
  seg[i] = merge(seg[i << 1], seg[(i << 1) | 1]);
}
signed main()
{
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  vector<pii> v(n);
  int ans = 0;
  for (int i = 0; i < n; i++)
  {
    cin >> v[i].fir >> v[i].sec.fir >> v[i].sec.sec;
    ans = max(ans, v[i].sec.fir);
  }
  vector<int> pref(n + 1, 0);
  for (int i = 0; i < n; i++)
  {
    pref[i + 1] = pref[i] + v[i].sec.fir;
  }
  sort(v.begin(), v.end());
  aux.assign(n, 0);
  for (int i = 1; i < n; i++)
  {
    aux[i] = v[i].sec.sec - (v[i].fir - v[i - 1].fir);
  }
  seg.resize(4 * n);
  build(0, n - 1, 1);
  for (int i = 0; i < n; i++)
  {
    int r = query(0, n - 1, 1, -v[i].sec.sec);
    if (r != -1)
    {
      int curr = pref[r + 1] - pref[i];
      ans = max(ans, curr);
    }
    if (i + 1 < n)
      update(1, 0, n - 1, i + 1, 0);
  }
  cout << ans << endl;
  return 0;
}

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52