0

Hi to all!

In the following code I am trying to implement a non-directed graph using adjacency lists. Even though there are no compilation errors, I don't get any results. When I am debugging the code it seems that there is a problem when I try to insert a second edge with the first node to be the node 1. More particular, the while-loop in the InsertEdge function seems not to end, a fact that is not logical and I can't figure out why is this happenning.

I would appreciate any help!Thanks in advance!

```
#include <iostream>
#include <fstream>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <math.h>
#include <limits.h>
using namespace std;
class Edge;
class Node
{
public:
int id;
bool visited;
Edge* adj;
int distance;
Node* previous;
Node(int);
~Node();
};
class Edge
{
public:
Node* initial; //first node
Node* next; //secong node of the edge
Edge* adj; //used to point the next edge stored in the adjacency list
int w;
Edge(Node*, Node*, int);
~Edge();
};
Node::Node(int a)
{
id=a;
visited=0;
adj=NULL; //used to point the first edge inserted in the adjacency list
//after the Node a.
previous=NULL;
distance=INT_MAX;
}
Node::~Node()
{
}
Edge::Edge(Node* a, Node* b, int weight)
{
initial=a;
next=b;
adj=NULL;
w=weight;
}
Edge::~Edge()
{
}
class MyGraph
{
protected:
Node* List[]; //stores all the nodes of the graph. Every node of the
//array points (List[]->adj) to a queue that contains
//all the edges starting from the same node.
public:
int Maxnodes;
int count;
Edge* Akmes[]; //stores all the edges of the graph
MyGraph(int);
~MyGraph();
Node* findnode(int);
void InsertEdge(int,int,int);
};
MyGraph::MyGraph(int size)
{
Maxnodes=size;
for (int i=1;i<=Maxnodes;i++)
{
List[i-1]=new Node(i);
}
count=0;
}
MyGraph::~MyGraph()
{
}
Node* MyGraph::findnode(int a)
{
Node* z;
for (int i=0;i<Maxnodes;i++)
{
if(List[i]->id==a)
z=List[i];
}
return z;
}
void MyGraph::InsertEdge(int x, int y, int w)
{
Node* a=findnode(x);
Node* b=findnode(y);
Edge* akmi=new Edge(a,b,w);
Akmes[count]=akmi;
count++;
Node* p;
Node* q;
Edge* l;
Edge* m;
p=List[x-1];
l=p->adj;
if (l==NULL)
p->adj=akmi;
else
{
while (l!=NULL)
l=l->adj;
l=akmi;
}
Edge* akmi2=new Edge(b,a,w); //I also insert edge <b,a> as my graph is
// undirected
q=List[y-1];
m=q->adj;
if (m==NULL)
q->adj=akmi2;
else
{
while (m!=NULL)
m=m->adj;
m=akmi2;
}
}
int main()
{
MyGraph* grafima=new MyGraph(5);
grafima->InsertEdge(1,2,3);
grafima->InsertEdge(2,3,4);
grafima->InsertEdge(3,5,6);
grafima->InsertEdge(1,4,7);
}
```