Submission #246798

#	Time	Username	Problem	Language	Result	Execution time	Memory
246798		srvlt	Meetings (IOI18_meetings)	C++14	36 / 100	844 ms	301604 KiB

meetings

#include "meetings.h"
#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;
#define ll long long
#define ld long double
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define SZ(x) (int)(x).size()
template <typename T> using ord_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int n = 5003, n2 = 1e5 + 123;
int mx[n][n], h[n2];
ll p[n][n], s[n][n];

struct Node {
	int l = 0, r = 0;
	int ans = 0, P = 0, S = 0;
	void clean() {
		l = r = ans = P = S = 0;
	}
};

Node merge(Node a, Node b) {
	if (a.l == 0 && a.r == 0) return b;
	Node c;
	c.l = a.l, c.r = b.r;
	c.P = a.P;
	if (a.P == a.r - a.l + 1)
		c.P += b.P;
	c.S = b.S;
	if (b.S == b.r - b.l + 1)
		c.S += a.S;
	c.ans = max({a.ans, b.ans, a.S + b.P});
	return c;
}
Node t[(1 << 18) + 1];

void build(int v, int l, int r) {
	t[v].l = l, t[v].r = r;
	if (l == r) {
		t[v].P = t[v].S = t[v].ans = (h[l - 1] == 1);
		return;
	}
	int m = l + r >> 1;
	build(v << 1, l, m);
	build(v << 1 | 1, m + 1, r);
	t[v] = merge(t[v << 1], t[v << 1 | 1]);
}
Node tmp;

void get(int v, int l, int r) {
	if (t[v].l > r || t[v].r < l) return;
	if (t[v].l >= l && t[v].r <= r) {
		tmp = merge(tmp, t[v]);
		return;
	}
	get(v << 1, l, r);
	get(v << 1 | 1, l, r);
}

int getans(int l, int r) {
	tmp.clean();
	get(1, l, r);
	return tmp.ans;
}

std::vector<long long> minimum_costs(std::vector<int> H, std::vector<int> L,
                                     std::vector<int> R) {
  int Q = L.size();
  std::vector<long long> C(Q);
  int N = SZ(H);
  for (int i = 0; i < N; i++) h[i] = H[i];
  
  if (N <= 5000 && Q <= 5000) {
	for (int i = 0; i < N; i++)
		for (int j = i; j < N; j++)
			mx[i][j] = (i == j) ? H[i] : max(mx[i][j - 1], H[j]);
	for (int j = 0; j < N; j++)
		for (int i = j; i >= 0; i--)
			p[i][j] = (i == j) ? H[i] : (p[i + 1][j] + mx[i][j]);
	for (int i = 0; i < N; i++)
		for (int j = i; j < N; j++)
			s[i][j] = (i == j) ? H[i] : (s[i][j - 1] + mx[i][j]);
	for (int i = 0; i < Q; i++) {
		int l = L[i], r = R[i];
		ll res = 1e18;
		for (int i = l; i <= r; i++)
			res = min(res, p[l][i] + s[i][r] - H[i]);
		C[i] = res;
	}
  }	else {
	  build(1, 1, N);
	  for (int i = 0; i < Q; i++) {
		  int l = L[i], r = R[i];
		  l++, r++;
		  C[i] = 2 * (r - l + 1) - getans(l, r);
	  }
  }
  return C;
}

Compilation message (stderr)

meetings.cpp: In function 'void build(int, int, int)':
meetings.cpp:48:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m = l + r >> 1;
          ~~^~~

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