I am trying to use the BFS method to search through my graph and then determine if there is a path between my two nodes. I understand it and can implement it with a linked list, but I am just having trouble grasping it with a matrix instead.
I believe I am going wrong in my looping section, I feel like I am iterating on the wrong thing, or maybe comparing the wrong values. Thanks for any help.
Here is the code I have:
#include <iostream>
#include <queue>
#include <string.h>
#include <stack>
#include <list>
using namespace std;
class Graph{
private:
int total_routes;
int total_stations;
public:
int AdjMatrix[100][100];
Graph(int routes, int stations);
void addRoute(int from, int to, int weight);
void printGraph();
bool isRoute(int from, int to);
};
Graph::Graph(int routes, int stations)
{
for(int i = 0; i < stations; i++){
for(int j=0; j < stations; j++){
AdjMatrix[i][j]=0;
}
}
total_routes = routes;
total_stations = stations;
}
void Graph::printGraph(){
cout << "\n" << endl;
for(int i = 0; i < total_stations; i ++){
for(int j = 0; j < total_stations; j++){
cout << " " << AdjMatrix[i][j];
}
cout << endl;
}
}
void Graph::addRoute(int from, int to, int weight){
AdjMatrix[from][to] = weight;
}
bool Graph::isRoute(int from, int to){
bool route = false;
bool visited[total_stations] = {false};
queue<int> verticies;
if (from == to){
cout << "Going into if its the same node statement" << endl;
return true;
}
visited[from] = true;
verticies.push(from);
cout << "Testing if there is a route from " << from << " To " << to << endl;
while(!verticies.empty() && route == false ){
int current;
current = verticies.front();
verticies.pop();
cout << "Going into for Loop, with a current value of " << current << endl;
for ( int i = AdjMatrix[current][0]; i < total_stations ; i++ ){
if (i == to ){
route = true;
break;
}
if ( visited[i] == false){
visited[i] = true;
verticies.push(i);
}
}
}
return route;
}
int main() {
Graph newGraph(2,10); //10 stations(Nodes), 2 routes
newGraph.addRoute(0,1,10); //Route from 1 to 2, with a weight of 10.
newGraph.addRoute(2,9,1); //Route of 2 to 9, with a weight of 1.
newGraph.printGraph();
bool answer = newGraph.isRoute(3,9); //Should say no route...
if (answer){
cout << "There is a route!" << endl;
}
else{
cout << "There is no route!" << endl;
}
return 0;
}
It would be better to initialize AdjMatrix[i][j] with NULL
Then you can do
for ( int i = 0; i < total_stations ; i++ ){
if (AdjMatrix[current][i]!=NULL)
{
if (i == to ){
route = true;
break;
}
if ( visited[i] == false){
visited[i] = true;
verticies.push(i);
}
}