Submission #706498

#	Time	Username	Problem	Language	Result	Execution time	Memory
706498		600Mihnea	Toll (APIO13_toll)	C++17	16 / 100	6 ms	212 KiB

toll

#include <cmath>
#include <functional>
#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <set>
#include <map>
#include <list>
#include <time.h>
#include <math.h>
#include <random>
#include <deque>
#include <queue>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <cassert>
#include <bitset>
#include <sstream>
#include <chrono>
#include <cstring>
#include <numeric>

using namespace std;

#define int long long

struct Dsu
{
	vector<int> t;
	int n;
	void init(int nn)
	{
		n = nn;
		t.clear();
		t.resize(n);
		iota(t.begin(), t.end(), 0);
	}
	int root(int a)
	{
		if (t[a] == a)
		{
			return a;
		}
		else
		{
			return t[a] = root(t[a]);
		}
	}
	bool join(int a, int b)
	{
		a = root(a);
		b = root(b);
		if (a == b)
		{
			return 0;
		}
		t[a] = b;
		return 1;
	}
};


struct Edge
{
	int a;
	int b;
	int cost;
};

bool operator < (Edge fi, Edge sc)
{
	return fi.cost < sc.cost;
}

signed main()
{
#ifdef ONPC	
	FILE* stream;
	freopen_s(&stream, "input.txt", "r", stdin);
#else
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#endif

	int n, m, k;
	cin >> n >> m >> k;
	vector<int> people(n);
	vector<Edge> edges;
	for (int i = 1; i <= m; i++)
	{
		int a, b, cost;
		cin >> a >> b >> cost;
		a--;
		b--;
		assert(0 <= a && a < n);
		assert(0 <= b && b < n);
		edges.push_back({ a, b, cost });
	}
	vector<pair<int, int>> spec;
	for (int i = 1; i <= k; i++)
	{
		int a, b;
		cin >> a >> b;
		a--;
		b--;
		assert(0 <= a && a < n);
		assert(0 <= b && b < n);
		spec.push_back({ a, b });
	}
	for (auto& p : people)
	{
		cin >> p;
	}
	sort(edges.begin(), edges.end());
	assert((int)edges.size() == m);
	assert((int)spec.size() == k);
	vector<int> ce(k, -1);
	set<pair<int, int>> sspec;

	for (int i = 0; i < k; i++)
	{
		int a = spec[i].first, b = spec[i].second;
		sspec.insert({a, b});
		Dsu dsu;
		dsu.init(n);

		for (auto& edge : edges)
		{
			dsu.join(edge.a, edge.b);
			if (dsu.root(a) == dsu.root(b))
			{
				ce[i] = edge.cost;
				break;
			}
		}
		assert(ce[i] != -1);
	}
	for (auto& edge : edges)
	{
		assert(!sspec.count({ edge.a, edge.b }));
		assert(!sspec.count({ edge.b, edge.a }));
	}
	int sol = -1;
	for (int mask = 0; mask < (1 << k); mask++)
	{
		vector<int> inds;
		for (int bit = 0; bit < k; bit++)
		{
			if (mask & (1 << bit))
			{
				inds.push_back(bit);
			}
		}
		vector<vector<pair<int, int>>> g(n);
		int nredges = 0;
		auto addedge = [&](int a, int b, int c)
		{
			nredges++;
			assert(0 <= a && a < n);
			assert(0 <= b && b < n);
			g[a].push_back({ b, c });
			g[b].push_back({ a, c });
		};
		bool fail = 0;
		Dsu dsu;
		dsu.init(n);
		for (auto& i : inds)
		{
			if (!dsu.join(spec[i].first, spec[i].second))
			{
				fail = 1;
				break;
			}
			addedge(spec[i].first, spec[i].second, ce[i]);
		}
		if (fail)
		{
			continue;
		}
		for (auto& edge : edges)
		{
			if (dsu.join(edge.a, edge.b))
			{
				addedge(edge.a, edge.b, edge.cost);
			}
		}
		assert(nredges == n - 1);
		vector<int> sub(n, 0), parof(n);
		int cur = 0;
		function<void(int, int)> build = [&](int a, int par)
		{
			parof[a] = par;
			sub[a] = people[a];
			for (auto& it : g[a])
			{
				int b = it.first, c = it.second;
				if (b == par)
				{
					continue;
				}
				build(b, a);
				sub[a] += sub[b];
				if (sspec.count({ a, b }) || sspec.count({ b, a }))
				{
					cur += sub[b] * c;
				}
			}
		};
		build(0, -1);
		for (int i = 0; i < n; i++)
		{
			for (auto& it : g[i])
			{
				if (it.first == parof[i])
				{
					continue;
				}
			}
		}
		//cout << " : " << cur << "\n";
		sol = max(sol, cur);
	}
	cout << sol << "\n";
	return 0;
}

• Subtask 1: 16 / 16
• Subtask 2: 0 / 18
• Subtask 3: 0 / 22
• Subtask 4: 0 / 22
• Subtask 5: 0 / 22