Submission #962580

#	Time	Username	Problem	Language	Result	Execution time	Memory
962580		MinaRagy06	Aliens (IOI16_aliens)	C++17	4 / 100	1 ms	348 KiB

aliens

#include <bits/stdc++.h>
#include "aliens.h"
#ifdef MINA
#include "grader.cpp"
#endif
using namespace std;
#define ll long long
#define lll __int128_t
#define sz(x) (int) x.size()

const int N = 100'005;
const ll inf = 1e18;
array<ll, 2> dp[N];
ll take_photos(int n, int crap, int m, vector<int> R, vector<int> C) {
	array<ll, 2> A[n + 1];
	vector<ll> v;
	for (int i = 1; i <= n; i++) {
		A[i] = {R[i - 1], C[i - 1]};
		if (A[i][0] > A[i][1]) swap(A[i][0], A[i][1]);
	}
	sort(A + 1, A + n + 1, [&] (array<ll, 2> x, array<ll, 2> y) {return make_pair(x[0], -x[1]) < make_pair(y[0], -y[1]);});
	multiset<ll> s;
	vector<array<ll, 2>> a = {{0, 0}};
	for (int i = 1; i <= n; i++) {
		while (s.size() && *s.begin() < A[i][0]) s.erase(s.begin());
		if (s.size() && A[i][1] <= *s.rbegin()) continue;
		a.push_back({A[i][0], A[i][1]});
		s.insert(A[i][1]);
	}
	n = a.size() - 1;
	ll prf[n + 2]{};
	prf[1] = -1e18;
	for (int i = 1; i <= n; i++) {
		prf[i + 1] = max(prf[i], a[i][1]);
		a[i][0]--;
		prf[i] = max(prf[i], a[i][0]);
		a[i][0] *= -2;
	}
	auto check = [&] (ll c) {
		for (int i = 1; i <= n; i++) {
			dp[i] = {inf, inf};
		}
		dp[0] = {0, 0};
		auto cmp = [&] (int x, int y, int z) {
			return (lll) (prf[y] * (prf[y] + a[y][0]) - prf[x] * (prf[x] + a[x][0]) - dp[y - 1][0] + dp[x - 1][0]) * (a[z][0] - a[y][0])
				>= (lll) (prf[z] * (prf[z] + a[z][0]) - prf[y] * (prf[y] + a[y][0]) - dp[z - 1][0] + dp[y - 1][0]) * (a[y][0] - a[x][0]);
		};
		auto calc = [&] (int i, int k) {
			return a[i][1] * a[k][0] - prf[k] * prf[k] - prf[k] * a[k][0] + dp[k - 1][0];
		};
		deque<int> dq;
		int sz = 0;
		for (int i = 1; i <= n; i++) {
			while (sz - 2 >= 0 && cmp(dq[sz - 2], dq[sz - 1], i)) {
				dq.pop_back();
				sz--;
			}
			dq.push_back(i);
			sz++;
			while (1 < sz && calc(i, dq[1]) <= calc(i, dq[0])) {
				dq.pop_front();
				sz--;
			}
			dp[i][0] = calc(i, dq[0]) + a[i][1] * a[i][1] + c;
			dp[i][1] = dp[dq[0] - 1][1] + 1;
		}
		return dp[n][1] <= m;
	};
	ll l = 0, r = inf;
	while (l <= r) {
		ll md = ((l + r) >> 1);
		if (check(md)) {
			r = md - 1;
		} else {
			l = md + 1;
		}
	}
	ll k = l;
	check(k);
	return dp[n][0] - k * m;
}

• Subtask 1: 4 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40