oj.uz

답안 #831257

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
831257 2023-08-20T02:47:11 Z PurpleCrayon Sky Walking (IOI19_walk) C++17
33 / 100
 247 ms 37568 KB 
#include "walk.h"
#include <bits/stdc++.h>
using namespace std;
 
#define sz(v) int(v.size())
#define ar array
typedef long long ll;
const int N = 2e5+10;
const ll INF = 1e18+10;
 
template <class T>
using min_pq = priority_queue<T, vector<T>, greater<T>>;

struct Solver {
	int n, m;
	vector<pair<int, int>> adj[N];
	ll dist[N];

	void clear() {
		for (int i = 0; i < N; i++) adj[i].clear();
	}
	
	void add_edge(int a, int b, int w) {
		adj[a].emplace_back(b, w);
		adj[b].emplace_back(a, w);
	}
	
	void dijkstra(int S) {
		fill(dist, dist + N, INF);
	
		min_pq<pair<ll, int>> pq;
		pq.push({dist[S] = 0, S});
	
		while (!pq.empty()) {
			auto [d_c, c] = pq.top(); pq.pop();
			if (dist[c] != d_c) continue;
			for (auto [nxt, w] : adj[c]) {
				if (dist[nxt] > dist[c] + w) {
					dist[nxt] = dist[c] + w;
					pq.push({dist[nxt], nxt});
				}
			}
		}
	}
	
	template <class T>
	vector<ll> solve(vector<int> h, vector<int> l, vector<int> r, vector<int> y, vector<T> base) {
		n = sz(h), m = sz(l);
		
		auto build = [&]() {
			vector<vector<int>> ev(n);
			for (int i = 0; i < m; i++) {
				ev[l[i]].push_back(i);
				ev[r[i]].push_back(i);
			}
	
			vector<bool> on(m);
			set<pair<int, int>> s;
			for (int i = 0; i < n; i++) {
				for (int x : ev[i]) if (!on[x]) {
					auto me = s.insert({y[x], x}).first;
	
					{
						auto it = next(me);
						if (it != s.end() && it->first <= h[i]) {
							add_edge(x, it->second, it->first - y[x]);
						}
					}
	
					{
						if (me != s.begin()) {
							auto it = prev(me);
							add_edge(x, it->second, y[x] - it->first);
						}
					}
				}
	
				for (int x : ev[i]) if (on[x]) {
					auto me = s.find({y[x], x});
					{
						auto it = next(me);
						if (it != s.end() && it->first <= h[i]) {
							add_edge(x, it->second, it->first - y[x]);
						}
					}
	
					{
						if (me != s.begin()) {
							auto it = prev(me);
							add_edge(x, it->second, y[x] - it->first);
						}
					}
	
					s.erase({y[x], x});
				}
	
				for (int x : ev[i]) on[x] = !on[x];
			}
		};
	
		build();
		int S = m;
		for (int i = 0; i < m; i++) if (l[i] == 0 && base[i] < INF) {
			add_edge(S, i, base[i]);
		}
		dijkstra(S);

		vector<ll> ans(m);
		for (int i = 0; i < m; i++) {
			ans[i] = dist[i];
		}
		return ans;
	}
};


Solver solver;

long long min_distance(vector<int> x, vector<int> h, vector<int> l, vector<int> r, vector<int> y, int s, int g) {
	int n = sz(x), m = sz(l);
	// assert(s == 0 && g == n-1);

	vector<ll> dist_left(m, INF);
	{
		vector<int> nh;
		for (int i = s; i >= 0; i--) {
			nh.push_back(h[i]);
		}

		vector<int> nl, nr, ny, ids;
		for (int i = 0; i < m; i++) if (l[i] <= s) {
			int L = l[i], R = min(s, r[i]);
			while (h[R] < y[i]) R--; // TODO optimize
			dist_left[i] = x[s] - x[R];

			nl.push_back(s - R); nr.push_back(s - L); ny.push_back(y[i]);
			ids.push_back(i);
		}

		solver.clear();
		auto calc = solver.solve(nh, nl, nr, ny, ny);
		for (int i = 0; i < sz(ids); i++) {
			dist_left[ids[i]] += calc[i];
		}
	}

	vector<ll> dist_right(m, INF);
	{
		vector<int> nh;
		for (int i = g; i < n; i++) {
			nh.push_back(h[i]);
		}

		vector<int> nl, nr, ny, ids;
		for (int i = 0; i < m; i++) if (g <= r[i]) {
			int L = max(g, l[i]), R = r[i];
			while (h[L] < y[i]) L++; // TODO optimize
			dist_right[i] = x[L] - x[g];
			// cerr << "> " << dist_right[i] << endl;

			nl.push_back(L - g); nr.push_back(R - g); ny.push_back(y[i]);
			ids.push_back(i);
		}

		solver.clear();
		auto calc = solver.solve(nh, nl, nr, ny, ny);
		for (int i = 0; i < sz(ids); i++) {
			dist_right[ids[i]] += calc[i];
		}
	}

	auto dist_mid = dist_left;
	{
		vector<int> nh;
		for (int i = s; i <= g; i++) {
			nh.push_back(h[i]);
		}

		vector<int> nl, nr, ny, ids;
		vector<ll> base;
		for (int i = 0; i < m; i++) if (r[i] >= s && l[i] <= g) {
			int L = max(s, l[i]), R = min(g, r[i]);
			while (L <= R && h[L] < y[i]) L++;
			while (R >= L && h[R] < y[i]) R--;
			if (L > R) continue;

			nl.push_back(L - s); nr.push_back(R - s); ny.push_back(y[i]);
			ids.push_back(i);
			base.push_back(dist_left[i]);
		}

		solver.clear();
		auto calc = solver.solve(nh, nl, nr, ny, base);
		for (int i = 0; i < sz(ids); i++) {
			int c = ids[i];
			dist_mid[c] = min(dist_mid[c], calc[i]);
		}
	}
	
	// cerr << "dists\n";
	// for (ll x : dist_left) cerr << x << ' ';
	// cerr << endl;

	// for (ll x : dist_mid) cerr << x << ' ';
	// cerr << endl;

	// for (ll x : dist_right) cerr << x << ' ';
	// cerr << endl;
	// cerr << "end dists\n";


	ll ans = INF;
	for (int i = 0; i < m; i++) {
		ans = min(ans, dist_mid[i] + dist_right[i]);
	}

	// cerr << x[n-1] - x[0] << ' ' << ans << endl;
	if (ans >= INF) return -1;
	return ans + x[g] - x[s];
}

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 4 ms 6488 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 3 ms 6484 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 64 ms 16868 KB Output is correct
2 Correct 136 ms 27808 KB Output is correct
3 Correct 140 ms 28392 KB Output is correct
4 Correct 191 ms 33364 KB Output is correct
5 Correct 231 ms 35076 KB Output is correct
6 Correct 209 ms 35964 KB Output is correct
7 Correct 91 ms 23016 KB Output is correct
8 Correct 91 ms 28128 KB Output is correct
9 Correct 247 ms 37532 KB Output is correct
10 Correct 162 ms 32556 KB Output is correct
11 Correct 12 ms 8992 KB Output is correct

Subtask #4
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 64 ms 16868 KB Output is correct
2 Correct 136 ms 27808 KB Output is correct
3 Correct 140 ms 28392 KB Output is correct
4 Correct 191 ms 33364 KB Output is correct
5 Correct 231 ms 35076 KB Output is correct
6 Correct 209 ms 35964 KB Output is correct
7 Correct 91 ms 23016 KB Output is correct
8 Correct 91 ms 28128 KB Output is correct
9 Correct 247 ms 37532 KB Output is correct
10 Correct 162 ms 32556 KB Output is correct
11 Correct 12 ms 8992 KB Output is correct
12 Correct 141 ms 28484 KB Output is correct
13 Correct 160 ms 33376 KB Output is correct
14 Correct 229 ms 35080 KB Output is correct
15 Correct 143 ms 30036 KB Output is correct
16 Correct 143 ms 33616 KB Output is correct
17 Correct 146 ms 31968 KB Output is correct
18 Correct 128 ms 30036 KB Output is correct
19 Correct 179 ms 33624 KB Output is correct
20 Correct 87 ms 23244 KB Output is correct
21 Correct 23 ms 11468 KB Output is correct
22 Correct 123 ms 29464 KB Output is correct
23 Correct 103 ms 29732 KB Output is correct
24 Correct 96 ms 28116 KB Output is correct
25 Correct 96 ms 28780 KB Output is correct
26 Correct 90 ms 26980 KB Output is correct
27 Correct 222 ms 35432 KB Output is correct
28 Correct 126 ms 33232 KB Output is correct
29 Correct 210 ms 35896 KB Output is correct
30 Correct 81 ms 23064 KB Output is correct
31 Correct 245 ms 37568 KB Output is correct
32 Correct 127 ms 29792 KB Output is correct
33 Correct 107 ms 29556 KB Output is correct
34 Correct 159 ms 33352 KB Output is correct
35 Correct 111 ms 30268 KB Output is correct
36 Correct 95 ms 29020 KB Output is correct
37 Correct 81 ms 27024 KB Output is correct
38 Correct 92 ms 28184 KB Output is correct
39 Correct 203 ms 35832 KB Output is correct
40 Correct 103 ms 28152 KB Output is correct
41 Correct 87 ms 28144 KB Output is correct

Subtask #5
0 / 43.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 4 ms 6488 KB Output isn't correct
2 Halted 0 ms 0 KB -