Submission #337712

#	Time	Username	Problem	Language	Result	Execution time	Memory
337712		BlancaHM	Dreaming (IOI13_dreaming)	C++14	59 / 100	1047 ms	17508 KiB

dreaming

#include <iostream>
#include <vector>
#include <queue>
#include <map>
#include <algorithm>
#include "dreaming.h"
using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
typedef vector<vpii> vvpii;

pii calcDist(int i, vvpii & G, vector<bool> & visited) {
	queue<int> Q;
	Q.push(i);
	int u, v, t, maxNode = i;
	vector<int> vertices = {};
	map<int, int> dist1, dist2;
	dist1[i] = 0;
	while(!Q.empty()) {
		u = Q.front();
		Q.pop();
		visited[u] = true;
		vertices.push_back(u);
		if (dist1[u] > dist1[maxNode])
			maxNode = u;
		for (auto connection: G[u]) {
			v = connection.first;
			t = connection.second;
			if (dist1.find(v) == dist1.end()) {
				dist1[v] = dist1[u]+t;
				Q.push(v);
			}
		}
	}
	dist2[maxNode] = 0;
	Q.push(maxNode);
	while(!Q.empty()) {
		u = Q.front();
		Q.pop();
		if (dist2[u] > dist2[maxNode])
			maxNode = u;
		for (auto connection: G[u]) {
			v = connection.first;
			t = connection.second;
			if (dist2.find(v) == dist2.end()) {
				dist2[v] = dist2[u]+t;
				Q.push(v);
			}
		}
	}
	int diam = dist2[maxNode];
	dist1.clear();
	dist1[maxNode] = 0;
	Q.push(maxNode);
	while(!Q.empty()) {
		u = Q.front();
		Q.pop();
		for (auto connection: G[u]) {
			v = connection.first;
			t = connection.second;
			if (dist1.find(v) == dist1.end()) {
				dist1[v] = dist1[u]+t;
				Q.push(v);
			}
		}
	}
	int ecc = 1e9;
	for (auto vert: vertices) {
		//cout << vert << " " << dist1[vert] << " " << dist2[vert] << "\n";
		ecc = min(ecc, max(dist1[vert], dist2[vert]));
	}
	return make_pair(ecc, diam);
}

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
	vvpii G(N, vpii());
	vector<bool> visited(N, false);
	for (int i = 0; i < M; i++) {
		G[A[i]].push_back(make_pair(B[i], T[i]));
		G[B[i]].push_back(make_pair(A[i], T[i]));
	}
	int CC = 0;
	vi diam = {}, ecc = {};
	pii curCC;
	for (int i = 0; i < N; i++) {
		if (!visited[i]) {
			curCC = calcDist(i, G, visited);
			ecc.push_back(curCC.first);
			diam.push_back(curCC.second);
			CC++;
		}
	}
	int ans = diam[0];
	for (int i = 1; i < CC; i++)
		ans = max(ans, diam[i]);
	sort(ecc.begin(), ecc.end(), greater<int>());
	for (int i = 1; i < CC; i++)
		ans = max(ans, ecc[i]+ecc[0]+L);
	for (int i = 1; i < CC; i++) {
		for (int j = i+1; j < CC; j++)
			ans = max(ans, ecc[i]+ecc[j]+2*L);
	}
	return ans;
}

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 0 / 18
• Subtask 5: 12 / 12
• Subtask 6: 0 / 23