This is my first time coding in C++ and I'm new to the generics in C++. I'm trying to make a little program that basically represents a graph and then traverse that graph using Breadth-First Search. I have made what I think is a generic graph and a generic BFS method. I have included all the code in case there is something I missed.
Here is the exact error:
no matching function for call to 'bfs(const char [4], Graph<std::__cxx11::basic_string<char> >&)
bfs("One", graph2);
Here is the code:
Graph.h :
#ifndef GRAPH_H
#define GRAPH_H
#include <map>
#include <iostream>
#include <list>
#include <set>
using namespace std;
template <class T>
class Graph{
private:
map<T, set<T>> adj_list;
public:
Graph();
void addVertex(T val, set<T> edges);
set<T> getNeighbours(T vertex);
};
#endif
Graph.cpp :
#include <iostream>
#include "Graph.h"
#include <string>
using namespace std;
template <class T>
Graph<T>:: Graph(){
;
}
// add vertex method
template <class T>
void Graph<T>:: addVertex(T val, set<T> edges){
//if the vertex is already created, the add the list of connections
//to that vertex, otherwise create a new vertex and create a new set
//of connections for the vertex
class map<T, set<T>> :: iterator it = adj_list.find(val);
if (it != adj_list.end()){
it->second.insert(edges.begin(), edges.end());
}
else{
adj_list.insert({val, edges});
}
// for all the connections, add the vertex to their corresponding
// connection set
for (T elem: edges){
class map<T, set<T>> :: iterator it1 = adj_list.find(elem);
if (it1 != adj_list.end()){
it1->second.insert(val);
}
else{
adj_list.insert({elem, {val}});
}
}
}
//get neighbours of given vertex
template <class T>
set<T> Graph<T>:: getNeighbours(T vertex){
return adj_list[vertex];
}
//override << operator. Display the adjacency list
template <class T>
inline ostream& operator<<(ostream& out, const Graph<T>& H){
out << "{\n";
for (class map<T, set<T>>::const_iterator it = H.adj_list.begin(), end = H.adj_list.end(); it != end;++it){
out << to_string(it->first) + " : ";
for (class set<T>::const_iterator lit = it->second.begin(), lend = it->second.end(); lit!= lend; ++lit){
if (distance(next(lit), lend) == 0){
out << to_string(*lit);
}
else{
out << to_string(*lit) + ", ";
}
}
out << "\n";
}
out << "}" << endl;
return out;
}
main.cpp :
#include <iostream>
#include "Graph.h"
#include "Graph.cpp"
#include <queue>
using namespace std;
template <class T>
void bfs(T vertex, Graph<T> graph){
// queue for bfs and set for checking if nodes have been visited
queue<T> myQueue;
set<T> visited;
//enqueue the vertex
myQueue.push(vertex);
//while there are still nodes to be visited
while (!myQueue.empty()){
//get the node to be searched next and add it to visited
T curr = myQueue.front();
myQueue.pop();
visited.insert(curr);
cout << "Visiting node:" << curr << endl;
//add all the nodes neighbours to the queue
for (T elem: graph.getNeighbours(curr)){
class set<T> :: iterator it = visited.find(elem);
//if the neighbours of the current node have been visitted then dont add to queue
if (it == visited.end()){
myQueue.push(elem);
}
}
}
}
int main(){
//initialize graph
Graph<int> graph1;
//create simple tree
// 1
// / \
// 2 3
// / \ / \
// 4 5 6 7
set<int> connections1 = {2, 3};
set<int> connections2 = {4, 5};
set<int> connections3 = {6, 7};
graph1.addVertex(1, connections1);
graph1.addVertex(2, connections2);
graph1.addVertex(3, connections3);
// perfrom BFS
bfs(1, graph1);
Graph<string> graph2;
set<string> connectionsS1 = {"Two", "Three"};
set<string> connectionsS2 = {"Four", "Five"};
set<string> connectionsS3 = {"Six", "Seven"};
graph2.addVertex("One", connectionsS1);
graph2.addVertex("Two", connectionsS2);
graph2.addVertex("Three", connectionsS3);
bfs("One", graph2);
return 0;
}
