C++ Programming Code Examples
C++ > Computer Graphics Code Examples
C++ Program to Check whether Graph is Biconnected
/* C++ Program to Check whether Graph is Biconnected */
#include <iostream>
#include <list>
#define NIL -1
using namespace std;
/* Class Declaration */
class Graph
{
private:
int V;
list<int> *adj;
bool isBCUtil(int v, bool visited[], int disc[], int low[],int parent[]);
public:
Graph(int V)
{
this->V = V;
adj = new list<int>[V];
}
void addEdge(int v, int w);
bool isBC();
};
/* Add Edge to connect v and w */
void Graph::addEdge(int v, int w)
{
adj[v].push_back(w);
adj[w].push_back(v);
}
/* A recursive function that returns true if there is an articulation point in given graph, otherwise returns false */
bool Graph::isBCUtil(int u, bool visited[], int disc[],int low[],int parent[])
{
static int time = 0;
int children = 0;
visited[u] = true;
disc[u] = low[u] = ++time;
list<int>::iterator i;
for (i = adj[u].begin(); i != adj[u].end(); ++i)
{
int v = *i;
if (!visited[v])
{
children++;
parent[v] = u;
if (isBCUtil(v, visited, disc, low, parent))
return true;
low[u] = min(low[u], low[v]);
if (parent[u] == NIL && children > 1)
return true;
if (parent[u] != NIL && low[v] >= disc[u])
return true;
}
else if (v != parent[u])
low[u] = min(low[u], disc[v]);
}
return false;
}
/* returns true if graph is Biconnected, otherwise false. */
bool Graph::isBC()
{
bool *visited = new bool[V];
int *disc = new int[V];
int *low = new int[V];
int *parent = new int[V];
for (int i = 0; i < V; i++)
{
parent[i] = NIL;
visited[i] = false;
}
if (isBCUtil(0, visited, disc, low, parent) == true)
return false;
for (int i = 0; i < V; i++)
if (visited[i] == false)
return false;
return true;
}
/* Main Contains Menu */
int main()
{
Graph g1(2);
g1.addEdge(0, 1);
if (g1.isBC())
cout<<"The Graph is BiConnected"<<endl;
else
cout<<"The Graph is not BiConnected"<<endl;
Graph g2(5);
g2.addEdge(1, 0);
g2.addEdge(0, 2);
g2.addEdge(2, 1);
g2.addEdge(0, 3);
g2.addEdge(3, 4);
g2.addEdge(2, 4);
if (g2.isBC())
cout<<"The Graph is BiConnected"<<endl;
else
cout<<"The Graph is not BiConnected"<<endl;
Graph g3(3);
g3.addEdge(0, 1);
g3.addEdge(1, 2);
if (g3.isBC())
cout<<"The Graph is BiConnected"<<endl;
else
cout<<"The Graph is not BiConnected"<<endl;
Graph g4(5);
g4.addEdge(1, 0);
g4.addEdge(0, 2);
g4.addEdge(2, 1);
g4.addEdge(0, 3);
g4.addEdge(3, 4);
if (g4.isBC())
cout<<"The Graph is BiConnected"<<endl;
else
cout<<"The Graph is not BiConnected"<<endl;
Graph g5(3);
g5.addEdge(0, 1);
g5.addEdge(1, 2);
g5.addEdge(2, 0);
if (g5.isBC())
cout<<"The Graph is BiConnected"<<endl;
else
cout<<"The Graph is not BiConnected"<<endl;
return 0;
}
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