Submission #1102007

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102007		NDT134	Graph (BOI20_graph)	C++14	58 / 100	1032 ms	9024 KiB

Graph

#include<iostream>
#include<vector>
#include<queue>
#include<cmath>
 
using namespace std;
using pi = pair<int, int>;
 
int main() {
	int n, M; cin >> n >> M;
	vector<vector<pi>> g(n);
	for (int i = 0; i < M; i++)
	{
		int x, y, z; cin >> x >> y >> z; x--; y--;
		g[x].push_back({ y, z });
		g[y].push_back({ x, z });
	}
	
	vector<pi> v(n, { -1 , 0 });
	vector<double> r(n, 0.1);
	bool b = 1;
	for (int i = 0; i < n; i++)
	{
		if (!v[i].second)
		{
			double a = 0.1;
			v[i] = { 0, 1 };
			vector<pi> c(1,v[i]);
			vector<int> aa(1, i);
			queue<int> q; q.push(i);
			while (!q.empty() && a == 0.1)
			{
				int x = q.front(); q.pop();
				for (pi p : g[x])
				{
					int y = p.first;
					if (!v[y].second)
					{
						v[y] = { -v[x].first + p.second,-v[x].second };
						c.push_back(v[y]);
						aa.push_back(y);
						q.push(y);
					}
					else
					{
						if (v[y].second != v[x].second)
						{
							if (v[x].first + v[y].first != p.second)
							{
								cout << "NO" << endl;
								return 0;
							}
						}
						else
						{
							a = 0.5 * (v[y].first + v[x].first - p.second) * (-v[x].second);
							break;
						}
					}
				}
				
			}
 
			if (a != 0.1)
			{
				while (!q.empty())
				{
					q.pop();
				}
				q.push(i);
				r[i] = a;
				while (!q.empty())
				{
					int x = q.front(); q.pop();
					for (pi p : g[x])
					{
						int y = p.first;
						double rr = 1.0*p.second - r[x];
						if (r[y] != 0.1 && r[y] != rr)
						{
							cout << "NO" << endl;
							return 0;
						}
						if (r[y] == 0.1)
						{
							r[y] = rr;
							q.push(y);
							v[y] = { -2, -2 };
						}
					}
				}
			}
			else
			{
				int x = 0;
				for (pi p : c)
				{
					x += abs(p.first);
				}
				int mn = x, i = 0;
				for (int m = -2*n; m <= 2*n; m++)
				{
					x = 0;
					for (pi p : c)
					{
						x += abs(p.first + p.second * m);
					}
					if (x < mn)
					{
						mn = x;
						i = m;
					}
				}
				
              
				for (int x : aa)
				{
					pi p = v[x];
					r[x] = p.first + p.second * i;
				}
			}
		}
	}
 
	cout << "YES" << endl;
	for (int i = 0; i < n; i++)
	{
		cout << r[i] << " ";
	}
	cout << endl;
	return 0;
}

Compilation message (stderr)

Graph.cpp: In function 'int main()':
Graph.cpp:21:7: warning: unused variable 'b' [-Wunused-variable]
   21 |  bool b = 1;
      |       ^

• Subtask 1: 5 / 5
• Subtask 2: 12 / 12
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 0 / 42