Submission #340603

#	Time	Username	Problem	Language	Result	Execution time	Memory
340603		VROOM_VARUN	Cake 3 (JOI19_cake3)	C++17	100 / 100	2867 ms	47596 KiB

cake3

/*
ID: varunra2
LANG: C++
TASK: cake3
*/

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

#define int long long

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e12
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions
int posl = 0, posr = 0;
int n, m;
VVI vals;
VI dp;

void init() {
  vals.resize(n);
  dp.assign(n, -INF);
}

struct segtree {
  int n;
  VI vals;
  VI pos;
  vector<bool> on;
  VII segtree;

  void init(VVI cake) {
    n = sz(cake);
    vals.resize(n);
    pos.resize(n);
    on.assign(n, false);
    for (int i = 0; i < n; i++) {
      swap(cake[i][0], cake[i][1]);
    }
    sort(all(cake), greater<VI>());
    for (int i = 0; i < n; i++) {
      pos[cake[i][2]] = i;
      vals[i] = cake[i][0];
    }
    segtree.assign(4 * n, MP(0, 0));
  }

  void merge(PII& a, PII& b, PII& c) { a = MP(b.x + c.x, b.y + c.y); }

  void upd(int ind, int cnt, int val, int node, int l, int r) {
    if (ind > r or ind < l) return;
    if (l == r) {
      segtree[node] = MP(val, cnt);
      return;
    }
    int mid = (l + r) / 2;
    upd(ind, cnt, val, 2 * node + 1, l, mid);
    upd(ind, cnt, val, 2 * node + 2, mid + 1, r);
    merge(segtree[node], segtree[2 * node + 1], segtree[2 * node + 2]);
  }

  int qry(int cnt, int node) {
    if (cnt <= 0) return 0;
    if (cnt >= segtree[node].y) return segtree[node].x;
    return qry(cnt, 2 * node + 1) +
           qry(cnt - segtree[2 * node + 1].y, 2 * node + 2);
  }
  void upd(int ind, int cnt, int val) { upd(ind, cnt, val, 0, 0, n - 1); }

  bool turn_on(int ind) {
    ind = pos[ind];
    if (on[ind]) return false;
    on[ind] = true;
    upd(ind, 1, vals[ind]);
    // debug("on", ind, vals[ind]);
    return true;
  }

  bool turn_off(int ind) {
    ind = pos[ind];
    if (on[ind] == false) return false;
    on[ind] = false;
    upd(ind, 0, 0);
    // debug("off", ind, vals[ind]);
    return true;
  }

  int qry() {
    int val = qry(m - 2, 0);
    // debug(posl, posr, val);
    return val;
  }
} st;

void shiftr(int r) {
  while (posr < r) {
    st.turn_on(++posr);
  }
  while (posr > r) {
    st.turn_off(posr--);
  }
}

void shiftl(int l) {
  while (posl < l) {
    st.turn_off(posl++);
  }
  while (posl > l) {
    st.turn_on(--posl);
  }
}

void activate(int l, int r) {
  if (posl > r) {
    shiftl(l);
    shiftr(r);
  } else {
    shiftr(r);
    shiftl(l);
  }
}

void dnc(int l, int r, int optl, int optr) {
  if (l > r) return;
  int mid = (l + r) / 2;
  PII ret = MP(-INF, 1);
  if (mid + m - 1 >= n) {
    dnc(l, mid - 1, optl, optr);
    return;
  }
  int start = max(mid + m - 1, optl);
  // debug(posl, posr, start);
  activate(mid + 1, start - 1);
  for (int i = start; i <= optr; i++) {
    int qr = st.qry();
    auto cur = MP(
        qr - 2 * (vals[i][0] - vals[mid][0]) + vals[i][1] + vals[mid][1], -i);
    // debug(cur, mid, qr, posl, posr);
    ret = max(ret, cur);
    st.turn_on(i);
    posr++;
  }
  dp[mid] = ret.x;
  int opt = -ret.y;
  // debug(ret, mid);
  dnc(l, mid - 1, optl, opt);
  dnc(mid + 1, r, opt, optr);
}

int32_t main() {
  // #ifndef ONLINE_JUDGE
  // freopen("cake3.in", "r", stdin);
  // freopen("cake3.out", "w", stdout);
  // #endif
  cin.sync_with_stdio(0);
  cin.tie(0);

  cin >> n >> m;

  init();

  for (int i = 0; i < n; i++) {
    int v, c;
    cin >> v >> c;
    vals[i] = {c, v};
  }

  sort(all(vals));

  // debug(vals);

  for (int i = 0; i < n; i++) {
    vals[i].PB(i);
  }

  st.init(vals);
  st.turn_on(0);

  dnc(0, n - 1, 0, n - 1);

  // debug(dp);

  cout << *max_element(all(dp)) << '\n';

  return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 76 / 76