Graph.cpp

#include <iostream>
#include <vector>
#include "Graph.h"
using namespace std;
void Graph::addNode(int node){
	int out;
	out = checkNode(node);
	if (out !=1 ){							//adds new node if it doesn't exist.
		nodeArray.push_back(node);
		cout << "Adding node: " << node << endl;
	}
	else{
		cout<<"The node already exists.\n";
	}
}

void Graph::addEdge(int node1, int node2){
	int a,check1,check2;
	a = checkEdge(node1, node2);
	check1=checkNode(node1);
	check2=checkNode(node2);
	if (a !=1 && check1 ==1 && check2 ==1 ){ //adds edge if the nodes to be connected exist and edge doesn't already exist.
		edge1Array.push_back(node1);
		edge2Array.push_back(node2);
		cout << "Adding edge: (" << node1 <<","<< node2 <<")\n";
	}
	else if(a==1){
		cout<<"The edge already exists.\n";
	}
	else if(check1 !=1){
		cout<<"The node "<< node1 <<" doesn't exist.\n";
	}
	else{
		cout<<"The node "<< node2 <<" doesn't exist.\n";
	}
	
}
void Graph::addUnEdge(int node1, int node2){			//adds undirected edges between two nodes.
	addEdge(node1,node2);
	addEdge(node2,node1);
}

int Graph::checkNode(int node){					//checks if node exists.
	
	for(int i=0; i< nodeArray.size(); i++){
		if (nodeArray[i] == node){
			// cout << "The node "<<node<<" exists.\n";
			return 1;
		}
	}
	return 0;
}
int Graph::checkEdge(int node1, int node2){				//checks if edge exists.
	for(int i=0; i< edge1Array.size(); i++){
		if (edge1Array[i] == node1 && edge2Array[i] == node2){
			cout<<"The required edge ("<<node1<<","<<node2<<") exists."<<endl;
			return 1;
		}
	}
	return 0;
}

void Graph::deleteNode(int node){					//deletes node if it exists.
	int out;
	out = checkNode(node);
	if (out ==1 ){
		int count = 0;
		for (vector<int>::const_iterator i = nodeArray.begin(); i < (nodeArray.end());i++){	//deletes node from vector
			
			if (*i == node){
				nodeArray.erase(nodeArray.begin() + count);
				cout<<"Node deleted successfully\n";
			}
			deleteUnEdge(node,*(nodeArray.begin() + count)); //deletes the edges with this node
			 if(count<nodeArray.size()-1){				//to delete last node of the array.
				count++;
			 } 
		}
	}
	else{
		cout<<"The required node doesn't exist.\n";
	}
}
void Graph::printNodeList(void){			//prints the nodes.
	for (vector<int>::const_iterator i = nodeArray.begin(); i < (nodeArray.end());i++){
		cout << "Node :" << (*i) <<endl;
	}
}
void Graph::deleteEdge(int node1, int node2){				//delete the edge if it exists.
	int a;
	a = checkEdge(node1, node2);
	if (a ==1 ){ 
		int count = 0;
		for (vector<int>::const_iterator i = edge1Array.begin(); i < (edge1Array.end());i++){
			if (*(edge1Array.begin() + count) == node1 && *(edge2Array.begin() + count) == node2){
				cout<<"Edge ("<<*(edge1Array.begin() + count)<<","<<*(edge2Array.begin() + count)<<") deleted successfully.\n";
				edge1Array.erase(edge1Array.begin() + count);
				edge2Array.erase(edge2Array.begin() + count);
			}
			if(count<edge1Array.size()-1){			// to delete the last edge of the array.
				count++; 
			}
		}
	}
}
void Graph::deleteUnEdge(int node1, int node2){			// delete undirected edges.
	deleteEdge(node1,node2);
	deleteEdge(node2,node1);
}
void Graph::printEdgeList(){
	cout<<"Edge List:\n";
	for(int i=0; i< edge1Array.size(); i++){
		cout<<"("<<edge1Array[i]<<","<<edge2Array[i]<<")"<<endl;
	}
}

void Graph::breadthfirstTraversal(int node){			//bfs to find friends of friends of a node.
	int x;
	x=checkNode(node);
	vector<int> friendArray;						// to store the friends of a node.
	if(x==1){
		int count=0;
		cout<<"Friends of "<<node <<":"<<endl;
		for (vector<int>::const_iterator i = edge1Array.begin(); i < (edge1Array.end());i++){		//finding friends
			if (*((edge1Array.begin() + count)) == node){
				friendArray.push_back(*(edge2Array.begin()+count));
				cout<<*(edge2Array.begin()+count)<<endl;
			}
			count++;
		}
		int count1=0;
		cout<<"Friends of friends of "<<node <<" are as follows."<<endl;
		for (vector<int>::const_iterator i = friendArray.begin(); i <(friendArray.end());i++){		//finding friends of friends
			int count2=0;
			cout<<"Friends of "<<*(friendArray.begin()+count1)<<":"<<endl;
			for (vector<int>::const_iterator itr = edge1Array.begin(); itr < (edge1Array.end());itr++){
				if (*((edge1Array.begin() + count2)) == *(friendArray.begin()+count1) && *(edge2Array.begin()+count2) != node){
					cout<<*(edge2Array.begin()+count2)<<endl;
				}
				count2++;	
			}
			count1++;
		}
	}

}