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#include <iostream>
#include <fstream>
#include <algorithm>
#include <math.h>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
class Graph
{
private:
bool m_oriented;
int m_nrNodes;
int m_nrEdges;
vector <int> m_nodes;
vector < vector <int> > m_neighborList;
void BFS(vector<bool>& visitedNodes, vector<int>& distances, int startNode = 0);
public:
Graph(int nrNodes = 0, int nrEdges = 0, bool oriented = false);
~Graph() {}
#pragma region Getters&Setters
void setOrientation(bool orientation)
{
m_oriented = orientation;
}
void setNrNodes(int nrNodes)
{
m_nrNodes = nrNodes;
}
void setNrEdges(int nrEdges)
{
m_nrEdges = nrEdges;
}
bool getOrientation()
{
return m_oriented;
}
int getNrNodes()
{
return m_nrNodes;
}
int getNrEdges()
{
return m_nrEdges;
}
#pragma endregion
void buildNeighborList(istream& input);
vector<int> minimalDistances(int startNode = 0);
};
Graph::Graph(int nrNodes, int nrEdges, bool oriented)
{
m_nrNodes = nrNodes;
m_nrEdges = nrEdges;
m_oriented = oriented;
for (int i = 0; i < nrNodes; i++)
{
vector <int> emptyVector;
m_neighborList.push_back(emptyVector);
}
}
void Graph::buildNeighborList(istream& input)
{
for (int i = 0; i < m_nrEdges; i++)
{
int node1, node2;
input >> node1 >> node2;
node1--;
node2--;
m_neighborList[node1].push_back(node2);
if (m_oriented == false)
{
m_neighborList[node2].push_back(node1);
}
}
}
void Graph::BFS(vector<bool>& visitedNodes, vector<int>& distances, int startNode)
{
queue<int> nodeOrder;
nodeOrder.push(startNode);
distances[startNode] = 0;
while (nodeOrder.empty() == false)
{
int currentNode = nodeOrder.front();
visitedNodes[currentNode] = true;
for (auto neighbor : m_neighborList[currentNode])
{
if (visitedNodes[neighbor] == false)
{
nodeOrder.push(neighbor);
distances[neighbor] = distances[currentNode] + 1;
visitedNodes[neighbor] = true;
}
}
nodeOrder.pop();
}
}
vector<int> Graph::minimalDistances(int startNode)
{
vector <bool> visited(m_nrNodes, false);
vector <int> distances(m_nrNodes, -1);
BFS(visited, distances, startNode);
return distances;
}
int main()
{
int nrNodes, nrEdges, startNode;
vector <int> distances;
fin >> nrNodes >> nrEdges >> startNode;
startNode--;
Graph graph(nrNodes, nrEdges, true);
graph.buildNeighborList(fin);
distances = graph.minimalDistances(startNode);
for (auto distance : distances)
{
fout << distance << " ";
}
fin.close();
fout.close();
return 0;
}