Submission #291900

#	Time	Username	Problem	Language	Result	Execution time	Memory
291900		Berted	Graph (BOI20_graph)	C++14	100 / 100	202 ms	20924 KiB

Graph

#include <iostream>
#include <bitset>
#include <iomanip>
#include <assert.h>
#include <vector>
#include <cmath>
#include <algorithm>
#include <queue>
 
#define vi vector<int>
#define pub push_back
#define pii pair<int, int>
#define fst first
#define snd second
#define vpi vector<pii>

const int INF = 1e9;

using namespace std;
 
int n, m, res[100001], sgn[100001], c[100001];
vpi adj[100001];
bitset<100001> vis;
vector<int> lol, mem;
int k = INF;

void dfs(int u)
{
	if (sgn[u]) {lol.push_back(c[u]);}
	else {lol.push_back(-c[u]);}
	mem.push_back(u);
	for (auto v : adj[u])
	{
		if (!vis[v.fst])
		{
			vis[v.fst] = 1;
			sgn[v.fst] = !sgn[u];
			c[v.fst] = 2 * v.snd - c[u];
			dfs(v.fst);
		}
		else
		{
			if (sgn[v.fst] != sgn[u] && c[v.fst] == 2 * v.snd - c[u]) continue;
			else if (sgn[v.fst] == sgn[u]) 
			{
				int r;
				if (sgn[v.fst])
				{
					r = c[v.fst] - (2 * v.snd - c[u]);
				}
				else
				{
					r = (2 * v.snd - c[u]) - c[v.fst];
				}
				r /= 2;
				if (k == INF || k == r) {k = r;}
				else {k = -INF;}
			}
			else {k = -INF;}
		}
	}
}
 

 
int main()
{
	ios :: sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cin >> n >> m;
	for (int i = 0; i < n; i++) {res[i] = 1000000;}
	for (int i = 0; i < m; i++)
	{
		int u, v, w;
		cin >> u >> v >> w;
		adj[u - 1].push_back({v - 1, w});
		adj[v - 1].push_back({u - 1, w});
	}
	bool val = 1;
	for (int i = 0; i < n && val; i++)
	{
		if (!vis[i])
		{
			vis[i] = 1; sgn[i] = 0; c[i] = 0;
			dfs(i);
			if (k == INF) 
			{
				nth_element(lol.begin(), lol.begin() + lol.size() / 2, lol.end());
				k = lol[lol.size() / 2];
			}
			if (k == -INF) {val = 0;}
			else
			{
				for (auto x : mem)
				{
					res[x] = c[x] + ((sgn[x]) ? (-k) : k);
				}
			}
			lol.clear();
			mem.clear();
			k = INF;
		}
	}
	if (val)
	{
		cout << "YES\n";
		for (int i = 0; i < n; i++)
		{
			cout << fixed << setprecision(6) << (double)res[i] / 2;
			if (i + 1 < n) cout << " ";
		}
		cout << "\n";
	}
	else {cout << "NO\n";}
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 12 / 12
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 42 / 42