File test.txt
6 (This is the number of vertices)
1 4 (Еhe first is the number of the vertex, and the second is the number of the vertex to which the edge is being constructed.
1 6
2 1
2 3
2 4
2 5
3 2
3 5
4 1
4 2
4 5
5 2
5 3
5 4
6 1
#include <iostream>
#include <fstream>
#include <vector>
#include <list>
using namespace std;
class edge
{
private:
int node2id, nodeid;
public:
edge(int id, int id2)
{
node2id = id2;
nodeid = id;
}
int getnodeid()
{
return nodeid;
}
int getnodeid2()
{
return node2id;
}
};
int main()
{
int totalnode, node1, node2;
ifstream input("test.txt");
input >> totalnode;
vector<list<edge>>adjList(totalnode);
while (input >> node1 >> node2)
{
adjList[node1 - 1].push_back(edge(node2, node1));
}
int c = 1;
vector<list<edge>>::iterator i;
for (i = adjList.begin(); i != adjList.end(); i++)
{
cout << c << " -- ";
list<edge> li = *i;
list<edge>::iterator iter;
for (iter = li.begin(); iter != li.end(); iter++)
{
cout << "[" << (*iter).getnodeid() << "] ";
}
cout << endl;
c++;
}
while (input >> node1 >> node2)
{
adjList[node1 - 1].push_back(edge(node1, node1));
}
cout << "\n";
And in this part, new vertices are created and I don't know how to remove the same ones.
vector<list<edge>>::iterator j;
for (j = adjList.begin(); j != adjList.end(); j++)
{
//cout << c << " -- ";
list<edge> li = *j;
list<edge>::iterator iter;
for (iter = li.begin(); iter != li.end(); iter++)
{
cout << c <<" -- " << "[" << (*iter).getnodeid2() << "] " << "[" << (*iter).getnodeid() << "]\n";
c++;
}
}
return 0;
}
Output
Adjacency list will be created
1 -- [2] [4] [6]
2 -- [1] [3] [4] [5]
3 -- [2] [5]
4 -- [1] [2] [5]
5 -- [2] [3] [4]
6 -- [1]
These vertices were created, but for example, vertices 7 and 10 (and so on) have the same connections. And you need to make sure that there are no identical vertices.
7 -- [1] [2]
8 -- [1] [4]
9 -- [1] [6]
10 -- [2] [1]
11 -- [2] [3]
12 -- [2] [4]
13 -- [2] [5]
14 -- [3] [2]
15 -- [3] [5]
16 -- [4] [1]
17 -- [4] [2]
18 -- [4] [5]
19 -- [5] [2]
20 -- [5] [3]
21 -- [5] [4]
22 -- [6] [1]
Based on what you have so far, seems like you don't really need a edge class. All the information could be stored in int instead.
And to solve what you wanted, you could first store all the edges in an std::vector<std::set<int> like:
while (input >> node1 >> node2)
{
adjList[node1 - 1].insert(node2);
}
By using a set, all the edges are stored in numerical ascending order. So instead of:
10 -- [2] [1]
You would have:
10 -- [1] [2]
Now you can just parse the vector into an std::map, like:
std::map<std::set<int>, int> tempMap;
for(auto i = 0; i < totalnode; ++i)
{
s.try_emplace(adjList[i], i);
}
This would automatically get rid of node that already have another node with the same set of adjacent nodes (like you described in your question).
However, I'm only calling this a tempMap because at the moment, they are ordered by their adjacencies, not their name.
So what you could do is:
std::map<int, std::set<int>> adjMap;
for(auto& [key, value] : tempMap)
{
adjMap.emplace(value, key);
}
Now you can loop through the entire map like:
for(auto& [node, edges] : adjMap
{
std::cout << node << " -- ";
for(auto& edge: edges)
{
std::cout << "[" << edge << "]";
}
std::cout << "\n";
}
Side note, I notice you have written code like:
vector<list<edge>>::iterator i;
for (i = adjList.begin(); i != adjList.end(); i++) { // your loop }
Instead, you could just use:
for(auto it = adjList.begin(); it != adjList.end(); ++it) { // your loop }
^^^^
It automatically assign i with the appropriate iterator type for that container.
Or even in many case:
for(auto& item : adjList) { // your loop }
And you can use item in your loop the same way as *i from previous example.