Submission #654514

#	Time	Username	Problem	Language	Result	Execution time	Memory
654514		pauloamed	Divide and conquer (IZhO14_divide)	C++14	100 / 100	140 ms	8124 KiB

divide

#include<bits/stdc++.h>
using namespace std;

#define int long long

const int MAXN = 200010;

struct BIT{
  int n; vector<int> v;
  BIT(int m = 0):n(m + 2), v(vector<int>(n, LLONG_MAX)){}

  int query(int i){ int ans = LLONG_MAX;
    for(i++; i > 0; i -= i & (-i))
      ans = min(ans, v[i]);
    return ans;
  }

  void update(int i, int val){
    for(i++; i < n; i += i & (-i)) 
      v[i] = min(val, v[i]);
  }
};

BIT bit(MAXN);

int X[MAXN], G[MAXN], E[MAXN];

int idx(vector<int> &v, int x){
  int n = v.size();
  int id = lower_bound(v.begin(), v.end(), x) - v.begin();
  return n - 1 - id;
}

int idx(int v[], int i){
  if(i < 0) return 0;
  else return v[i];
}

int32_t main(){
  int n; cin >> n;
  vector<int> vals;

  int e_accu = 0;
  for(int i = 0; i < n; ++i){
    cin >> X[i] >> G[i] >> E[i]; 
    if(i) E[i] += E[i - 1];
    if(i) G[i] += G[i - 1];

    int Iq = X[i] - E[i];
    int Iu = X[i] - idx(E, i - 1);

    vals.push_back(Iq);
    vals.push_back(Iu);
  }

  sort(vals.begin(), vals.end());
  vals.erase(unique(vals.begin(), vals.end()), vals.end());

  int ans = 0;
  for(int i = 0; i < n; ++i){
    int Iq = X[i] - E[i];
    int Iu = X[i] - idx(E, i - 1);

    Iq = idx(vals, Iq);
    Iu = idx(vals, Iu);

    bit.update(Iu, idx(G, i - 1));
    int best = bit.query(Iq);


    ans = max(ans, G[i] - best);
  }
  cout << ans << "\n";
}

Compilation message (stderr)

divide.cpp: In function 'int32_t main()':
divide.cpp:43:7: warning: unused variable 'e_accu' [-Wunused-variable]
   43 |   int e_accu = 0;
      |       ^~~~~~

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