Submission #781901

#	Time	Username	Problem	Language	Result	Execution time	Memory
781901		Sam_a17	Radio Towers (IOI22_towers)	C++17	0 / 100	821 ms	30236 KiB

towers

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;
 
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
 
#define sz(x) (int)x.size()
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount
 
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long
 
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
 
// Indexed Set  
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
// template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(Tree <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
 
 
// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);
 
// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
 
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
// void setIO(string str = "") {
//   fastIO();
 
//   if(str == "input") {
//     freopen("input.txt", "r", stdin);
//     freopen("output.txt", "w", stdout);
//   } else if(str != "") {
//     freopen((str + ".in").c_str(), "r", stdin);
//     freopen((str + ".out").c_str(), "w", stdout);
//   }
// }

const int N = 2e5 + 10;
int a[N], mid = -1;
int f1 = 1, n;
vector<int> b;
int pi[N];

vector<pair<long long, int>> ai;


struct segTreeMax {
  vector<long long> mTree;
  int size;
 
  void init(long long n) {
    size = 1;
    while(size < n)  {
      size *= 2;
    }
    mTree.assign(2 * size - 1, 0);
  }
 
  void upd(int u, long long v, int x, int lx, int rx) { // set value at pos u
    if(rx - lx == 1) {
      mTree[x] = v;
      return;
    }
 
    int m = (lx + rx) / 2;
    if(u < m) {
      upd(u, v, 2 * x + 1, lx, m);
    }else {
      upd(u, v, 2 * x + 2, m, rx);
    }
    mTree[x] = max(mTree[2 * x + 1], mTree[2 * x + 2]);
  }
 
  void upd(int u, long long v) {
    upd(u, v, 0, 0, size);
  }
 
  long long qry (int l, int r, int x, int lx, int rx) { // range queries
    if(l >= rx || lx >= r) {
      return 0;
    }
    if(lx >= l && r >= rx) {
      return mTree[x];
    }
 
    int m = (rx + lx) / 2;
    long long s1 = qry(l, r, 2 * x + 1, lx, m);
    long long s2 = qry(l, r, 2 * x + 2, m, rx);
    return max(s1, s2);
  }
 
  long long qry(int l, int r) {
    if(l >= r) {
      return -1;
    } 
    return qry(l, r, 0, 0, size);
  }

  int find(long long k, int l, int x, int lx, int rx) {
    if (mTree[x] < k) {
      return -1;
    }

    if (rx <= l) {
      return -1;
    }
 
    if(rx - lx == 1) {
      return lx;
    }
 
    int mid = (lx + rx) / 2;
    int answ = find(k, l, 2 * x + 1, lx, mid);
 
    if (answ == -1) {
      answ = find(k, l, 2 * x + 2, mid, rx);
    }
    return answ;
  }
 
  int find(long long k, int l) {
    return find(k, l, 0, 0, size);
  }
};

struct segTree {
  struct node {
    long long max_d, min_d;
    long long max_dist;
  };
  vector<node> mTree;
  int size;

  node merge(node a, node b) {
    a.max_d = max(a.max_d, b.max_d);
    a.min_d = min(a.min_d, b.min_d);
    a.max_dist = max({a.max_dist, b.max_dist, a.max_d - b.min_d});
    return a;
  }
 
  void init(long long n) {
    size = 1;
    while(size < n)  {
      size *= 2;
    }
    mTree.assign(2 * size - 1, {-1, -1, 0});
  }
 
  void upd(int u, long long v, int x, int lx, int rx) { // set value at pos u
    if(rx - lx == 1) {
      mTree[x].max_d = mTree[x].min_d = v;
      mTree[x].max_dist = 0;
      return;
    }
 
    int m = (lx + rx) / 2;
    if(u < m) {
      upd(u, v, 2 * x + 1, lx, m);
    }else {
      upd(u, v, 2 * x + 2, m, rx);
    }
    mTree[x] = merge(mTree[2 * x + 1], mTree[2 * x + 2]);
  }
 
  void upd(int u, long long v) {
    upd(u, v, 0, 0, size);
  }
 
  node qry (int l, int r, int x, int lx, int rx) { // range queries
    if(l >= rx || lx >= r) {
      return {0, 0, 0};
    }
    if(lx >= l && r >= rx) {
      return mTree[x];
    }
 
    int m = (rx + lx) / 2;
    node s1 = qry(l, r, 2 * x + 1, lx, m);
    node s2 = qry(l, r, 2 * x + 2, m, rx);
    return merge(s1, s2);
  }
 
  node qry(int l, int r) {
    return qry(l, r, 0, 0, size);
  }
};

struct mergeSortTree {
  vector<vector<int>> mTree;
  int size;

  void merge(int x, vector<int>& li, vector<int>& ri) {
    int l = 0, r = 0;
    while (l < sz(li) || r < sz(ri)) {
      if(l < sz(li) && r < sz(ri)) {
        if(li[l] < ri[r]) {
          mTree[x].push_back(li[l++]);
        } else {
          mTree[x].push_back(ri[r++]);
        }
      } else if(l < sz(li)) {
        mTree[x].push_back(li[l++]);
      } else {
        mTree[x].push_back(ri[r++]);
      }
    }
  }

  void build(int x, int lx, int rx) {
    if(rx - lx == 1) {
      if(lx < n) {
        mTree[x].push_back(ai[lx].second);
      }
    } else {
      int mid = (lx + rx) / 2;
      build(2 * x + 1, lx, mid);
      build(2 * x + 2, mid, rx);
      merge(x, mTree[2 * x + 1], mTree[2 * x + 2]);
    }
  }

  void init(long long n) {
    size = 1;
    while(size < n)  {
      size *= 2;
    }
    mTree.assign(2 * size - 1, {});
    build(0, 0, size);
  }
 
  int qry (int l, int r, int lix, int rix, int x, int lx, int rx) {
    if(l >= rx || lx >= r) {
      return 0;
    }

    if(lx >= l && r >= rx) {
      auto itl = lower_bound(all(mTree[x]), lix);
      if(itl == mTree[x].end()) return 0;
      int indl = itl - mTree[x].begin();

      auto indr = upper_bound(all(mTree[x]), rix) - mTree[x].begin() - 1;
      
      if(indl <= indr) {
        return indr - indl + 1;
      } else {
        return 0;
      }
    }
 
    int m = (rx + lx) / 2;
    int s1 = qry(l, r, lix, rix, 2 * x + 1, lx, m);
    int s2 = qry(l, r, lix, rix, 2 * x + 2, m, rx);
    return s1 + s2;
  }
 
  int qry(int l, int r, int lix, int rix) {
    return qry(l, r, lix, rix, 0, 0, size);
  }

  pair<int, int> qry2(int l, int r, int lix, int rix, int x, int lx, int rx) {
    if(l >= rx || lx >= r) {
      return {n, -1};
    }

    if(lx >= l && r >= rx) {
      auto itl = lower_bound(all(mTree[x]), lix);
      if(itl == mTree[x].end()) return {n, -1};
      int indl = itl - mTree[x].begin();

      auto indr = upper_bound(all(mTree[x]), rix) - mTree[x].begin() - 1;
      if(indl <= indr) {
        return {indl, indr};
      } else {
        return {n, -1};
      }
    }
 
    int m = (rx + lx) / 2;
    pair<int, int> s1 = qry2(l, r, lix, rix, 2 * x + 1, lx, m);
    pair<int, int> s2 = qry2(l, r, lix, rix, 2 * x + 2, m, rx);
    return {min(s1.first, s2.first), max(s1.second, s2.second)};
  }
 
  pair<int, int> qry2(int l, int r, int lix, int rix) {
    return qry2(l, r, lix, rix, 0, 0, size);
  }
};


segTree segt;
segTreeMax seg_all;
mergeSortTree mt;

void init(int maxN, std::vector<int> H) {
  n = maxN;

  seg_all.init(n + 1);
  for(int i = 0; i < n; i++) {
    a[i] = H[i];
    seg_all.upd(i, a[i]);
  }
  
  vector<int> lowRig(n + 1, n), lowLef(n + 1, -1);
  stack<pair<int, int>> st;
  segt.init(n + 1);

  for(int i = 0; i < n; i++) {
    segt.upd(i, a[i]);
    while(!st.empty() && st.top().first > a[i]) {
      lowRig[st.top().second] = i;
      st.pop();
    }

    if(!st.empty()) {
      lowLef[i] = st.top().second;
    }
    st.push({a[i], i});
  }

  for(int i = 0; i < n; i++) {
    long long curl = seg_all.qry(lowLef[i] + 1, i);
    if(lowLef[i] == -1) curl = 1e10 + 10;
    long long curr = seg_all.qry(i + 1, lowRig[i]);
    if(lowRig[i] == n) curr = 1e10 + 10;
    ai.push_back({min(curl, curr) - a[i], i});
  }

  sort(all(ai));

  mt.init(n + 1);
}

int max_towers(int L, int R, int D) {

  //
  // if(L == 0 && R == n - 1) {
  //   auto it = lower_bound(all(ai), (long long )D);
  //   int answ = 1;
  //   if(it != ai.end()) {
  //     int ind = it - ai.begin();
  //     answ = max(answ, n - ind);
  //   }
  //   return answ;
  // }

  //
  auto it = lower_bound(all(ai), make_pair((long long) D, 0));
  if(it == ai.end()) {
    return 1;
  }

  int ind = it - ai.begin();
  int ans = mt.qry(ind, n, L, R);
  pair<int, int> pr = mt.qry2(ind, n, L, R);

  if(pr.first <= pr.second) {
    int indi = seg_all.find(a[pr.second] + D, pr.second + 1);
    if(indi <= pr.second) {
      int delta = segt.qry(indi, pr.second + 1).max_dist;
      if(delta >= D) {
        ans++;
      }
    }
  }
  
  return ans;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 11
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 17
• Subtask 6: 0 / 19
• Subtask 7: 0 / 23