Submission #756864

#	Time	Username	Problem	Language	Result	Execution time	Memory
756864		DarkMatter	Cyberland (APIO23_cyberland)	C++17	78 / 100	1189 ms	24048 KiB

cyberland

#include "cyberland.h"

/* 	* In the name of GOD  */

#include "bits/stdc++.h"

using namespace std;

typedef long long ll;
typedef long double ld;
#define F first
#define S second
#define mk make_pair
const ll N = 2e5 + 10, INF = 2e18 + 10;
vector <pair <int, ll>> g[N];
ld dis[N], od[N], x[N];
int n, h;
bool vis[N];
vector <int> ww;

void dijkstra() {
	priority_queue <pair <ld, int>> q;
	for (int s = 0; s < n; s++)
		q.push(make_pair((ld)-1.0 * dis[s], s));
	while (!q.empty()) {
		pair <ld, int> p = (q.top());
		int x = p.S;
		q.pop();
		if (dis[x] != -1 * p.F || x == h)
			continue;
		ld d = dis[x];
		for (auto [y, w] : g[x]) {
			if (dis[y] <= d + w) {
				continue;
			}
			dis[y] = d + w;
			q.push(make_pair(-1 * dis[y], y));
		}
	}
}

void dfs(int v) {
	vis[v] = true;
	for (auto [u, w] : g[v]) {
		if (!vis[u])
			dfs(u);
	}
}

void dfs2(int v) {
	vis[v] = true;
	ww.push_back(v);
	for (auto [u, w] : g[v]) {
		if (!vis[u] && u != h)
			dfs2(u);
	}
}

double solve(int N, int M, int K, int H, std::vector<int> x, std::vector<int> y, std::vector<int> c, std::vector<int> arr) {
	K = min(K, 70);
	n = N;
	h = H;
	for (int i = 0; i <= n; i++)
		g[i].clear(), vis[i] = false;
	for (int i = 0; i < M; i++) {
		g[x[i]].push_back(mk(y[i], c[i]));
		g[y[i]].push_back(mk(x[i], c[i]));
	}
	dfs(0);
	if (!vis[H]) {
		for (int i = 0; i <= n; i++)
			g[i].clear(), vis[i] = false;
		return -1;
	}
	for (int i = 0; i < n; i++) {
		dis[i] = INF;
	}
	for (int i = 0; i <= n; i++)
		vis[i] = false;
	ww.clear();
	dfs2(0);
	for (int i : ww) {
		if (i == 0 || arr[i] == 0)
			dis[i] = 0;
	}
	ld mn = INF;
	for (int i = 0; i <= K; i++) {
		dijkstra();
		mn = min(mn, dis[H]);
		dis[H] = INF;
		for (int i = 0; i < n; i++)
			od[i] = dis[i];
		for (int i = 0; i < n; i++) {
			if (arr[i] == 2) {
				ld mnn = INF;
				for (auto [j, w] : g[i]) {
					mnn = min(mnn, od[j] + w);
				}
				dis[i] = min(dis[i], (mnn) / (ld)2);
			}
		}
	}
	for (int i = 0; i <= n; i++)
		g[i].clear(), vis[i] = false;
	return mn;
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 13 / 13
• Subtask 4: 0 / 19
• Subtask 5: 7 / 7
• Subtask 6: 16 / 16
• Subtask 7: 29 / 29
• Subtask 8: 0 / 3