Submission #977647

#	Time	Username	Problem	Language	Result	Execution time	Memory
977647		happypotato	Meetings (IOI18_meetings)	C++17	36 / 100	600 ms	209048 KiB

meetings

#include "meetings.h"
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
struct info {
	int ans, lmax, rmax;
	bool full;
	info(int x = 0): ans(x), lmax(x), rmax(x), full(x) {};
};
info merge(info lhs, info rhs) {
	info res;
	res.lmax = (lhs.full ? lhs.lmax + rhs.lmax : lhs.lmax);
	res.rmax = (rhs.full ? rhs.rmax + lhs.rmax : rhs.rmax);
	res.ans = max({lhs.ans, rhs.ans, lhs.rmax + rhs.lmax});
	res.full = (lhs.full && rhs.full);
	return res;
}
const int mxN = 1e5 + 10;
info seg[4 * mxN];
bool a[mxN];
int n;
void build(int l = 0, int r = n - 1, int idx = 1) {
	if (l == r) {
		seg[idx] = info(!a[l]);
		return;
	}
	int mid = (l + r) >> 1;
	build(l, mid, (idx << 1));
	build(mid + 1, r, (idx << 1) | 1);
	seg[idx] = merge(seg[(idx << 1)], seg[(idx << 1) | 1]);
}
info query(int tl, int tr, int l = 0, int r = n - 1, int idx = 1) {
	if (tl <= l && r <= tr) return seg[idx];
	int mid = (l + r) >> 1;
	if (tr <= mid) return query(tl, tr, l, mid, (idx << 1));
	if (tl > mid) return query(tl, tr, mid + 1, r, (idx << 1) | 1);
	return merge(query(tl, tr, l, mid, (idx << 1)), query(tl, tr, mid + 1, r, (idx << 1) | 1));
}
vector<long long> minimum_costs(vector<int32_t> H, vector<int32_t> L,
								vector<int32_t> R) {
	
	n = H.size();

	if (n <= 5000) {
		vector<int> ans;
		int precomp[n][n];
		for (int i = 0; i < n; i++) {
			precomp[i][i] = H[i];
			int maxi;
			maxi = H[i];
			for (int j = i - 1; j >= 0; j--) {
				maxi = max(maxi, 1LL * H[j]);
				precomp[i][j] = precomp[i][j + 1] + maxi;
			}
			maxi = H[i];
			for (int j = i + 1; j < n; j++) {
				maxi = max(maxi, 1LL * H[j]);
				precomp[i][j] = precomp[i][j - 1] + maxi;
			}
		}
		for (int i = 0; i < (int)(L.size()); i++) {
			int l = L[i], r = R[i];
			int cur = 1e18;
			for (int j = l; j <= r; j++) {
				cur = min(cur, precomp[j][l] + precomp[j][r] - precomp[j][j]);
			}
			// cerr << l << ' ' << r << ' ' << cur << endl;
			ans.pb(cur);
		}
		return ans;
	}
	
	for (int i = 0; i < n; i++) a[i] = (H[i] == 2);
	build();
	vector<int> ans;
	for (int i = 0; i < (int)(L.size()); i++) {
		// cerr << L[i] << ' ' << R[i] << ' ' << query(L[i], R[i]).ans << endl;
		ans.pb(2LL * (R[i] - L[i] + 1) - query(L[i], R[i]).ans);
	}
	return ans;
}
#undef int

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