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#include <vector>
#include <queue>
#include <fstream>
#include <iostream>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
#define NO_PATH -1
/**
* @brief Graph class that implements algorithms
*
*/
class Graph
{
private:
// Number of nodes in the Graph
int numberOfNodes;
// If the Graph is oriented
bool isOriented;
// Edges in the Graph
vector<vector<int> > edges;
public:
/**
* @brief Construct a new Graph object
*
* @param numberOfNodes
* @param isOriented
*/
Graph(int numberOfNodes, bool isOriented)
{
this->numberOfNodes = numberOfNodes;
this->isOriented = isOriented;
}
/**
* @brief Read the edges from a stream
*
* @param in
* @param numberOfEdges
* @param isZeroBased
*/
void readEdges(istream &in, int numberOfEdges, bool isZeroBased)
{
// Create vectors for every node
for (int i = 0; i < numberOfNodes; i++)
{
vector<int> targetNodes;
edges.push_back(targetNodes);
}
for (int i = 0; i < numberOfEdges; i++)
{
int baseNode, targetNode;
in >> baseNode >> targetNode;
// Make nodes zero-based
if (!isZeroBased)
{
baseNode--;
targetNode--;
}
// Add edges
edges[baseNode].push_back(targetNode);
if (!isOriented)
{
edges[targetNode].push_back(baseNode);
}
}
}
/**
* @brief Get the minimum distances
*
* @param startNode
* @param distances array where the distances will be placed. It should have [number_of_nodes] elements
*/
void getMinimumDistances(int startNode, int distances[])
{
queue<int> bfsNodesQueue;
bool isVisited[numberOfNodes];
for (int i = 0; i < numberOfNodes; i++)
{
isVisited[i] = false;
distances[i] = NO_PATH;
}
// Add the start node to the distances queue. The distance is 0
bfsNodesQueue.push(startNode);
distances[startNode] = 0;
isVisited[startNode] = true;
// BFS
while (!bfsNodesQueue.empty())
{
int currentNode = bfsNodesQueue.front();
int currentDistance = distances[currentNode];
for (int i = 0; i < edges[currentNode].size(); i++)
{
int targetNode = edges[currentNode][i];
if (!isVisited[targetNode])
{
// If node is not visited add it to the queue and update the distance
bfsNodesQueue.push(targetNode);
distances[targetNode] = currentDistance + 1;
isVisited[targetNode] = true;
}
}
bfsNodesQueue.pop();
}
}
};
int main()
{
int numberOfNodes, numberOfEdges, startNode;
fin >> numberOfNodes >> numberOfEdges >> startNode;
startNode--; // make it zero-based
Graph graph(numberOfNodes, true);
graph.readEdges(fin, numberOfEdges, false);
int distances[numberOfNodes];
graph.getMinimumDistances(startNode, distances);
for (int i = 0; i < numberOfNodes; i++)
{
fout << distances[i] << " ";
}
}