Cod sursa(job #1953638)

Utilizator SolcanMihaiSolcan Mihai Andrei SolcanMihai Data 4 aprilie 2017 22:15:21
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

const int N = 50500;
const int inf = (1 << 20);

int n, m;
vector<pair<int, int> > vecini[N];
queue<int> Q;
int dist[N];
int viz[N];

void citire()
{
	scanf("%d %d", &n, &m);

	int tmp1, tmp2, tmp3;

	for(int i = 1; i <= m; i++)
	{
		scanf("%d %d %d", &tmp1, &tmp2, &tmp3);
		
		vecini[tmp1].push_back(make_pair(tmp3, tmp2));
	}

	for(int i = 1; i <= n; i++)
	{
		viz[i] = 0;
		dist[i] = inf;
	}
}

int solve()
{
	Q.push(1);
	viz[1] = 1;
	dist[1] = 0;

	while(Q.empty() == false)
	{
		int x = Q.front();
		Q.pop();

		int l = vecini[x].size();

		for(int i = 0; i < l; i++)
		{
			if(dist[vecini[x][i].second] == inf || dist[vecini[x][i].second] > dist[x] + vecini[x][i].first)
			{
				dist[vecini[x][i].second] = dist[x] + vecini[x][i].first;
				viz[vecini[x][i].second]++;

				if(viz[vecini[x][i].second] > n)
				{
					return false;
				}

				Q.push(vecini[x][i].second);
			}
		}
	}

	return true;
}

void afisare()
{
	for(int i = 2; i <= n; i++)
	{
		if(viz[i] == inf)
		{
			printf("0 ");
			continue;
		}

		printf("%d ", dist[i]);
	}
}

int main()
{
	freopen("bellmanford.in", "r", stdin);
	freopen("bellmanford.out", "w", stdout);

	citire();

	if(solve() == false)
	{
		printf("Ciclu negativ!");
	}
	else
	{
		afisare();
	}

	return 0;
}