Question

1. a. Using C++, represent the following graph using adjacency matrix, and implement DFS by using stack (define it using class) to traverse the graph. b. Similarly, implement BFS (define queue using class) to traverse the graph c.When node 6 is printed, what numbers are in the stack (for DFS) and queue (for BFS) respectively? Draw pictures to show them.

Answer 1

//C++ program

#include<iostream>
using namespace std;

template <class T>
class queue{
   private:
       T *arr;
       int front,rear,capacity;
      
   public:
       queue(int size){
           capacity=size;
           front=-1;
           rear =-1;
           arr = new T[capacity];
          
       }
       bool empty(){
           return front==-1;
       }
       bool full(){
           return (rear+1)%capacity==front;
       }
       void enqueue(T data){
           rear++;
       rear%=capacity;
       arr[rear]=data;
       if(front==-1)front=rear;
       }
       T frontElement(){
           return arr[front];
       }
       void dequeue(){
       if(front==rear)
           front=rear=-1;
       else{
       front++;
       front%=capacity;}
       }
};

class graph{
   private:
   int **arr;
   int v;
  
public:
   graph(int v){
       this->v=v;
      
       arr=new int* [this->v];
       for(int i=0;i<this->v;i++)
       this->arr[i]=new int[this->v];
       for(int i=0;i<this->v;i++){
           for(int j=0;j<this->v;j++)
           this->arr[i][j]=0;
       }
   }
   bool addEdge(int fromVertex , int toVertex ){
       if(fromVertex<0||fromVertex>=v||toVertex<0||toVertex>=v)return false;
       this->arr[fromVertex][toVertex]=1;
       this->arr[toVertex][fromVertex]=1;
       return true;
   }
  
   void RecDFS(int s, bool visited[])
   {
  
visited[s] = true;
cout << s << " ";

for (int i = 0; i <v; ++i)
if (!visited[i]&&arr[s][i]==1)
RecDFS(i, visited);
           }

void DFS(int source)
{
  
bool *visited = new bool[v];
for (int i = 0; i < v; i++)
visited[i] = false;

RecDFS(source, visited);
   }
  
   void BFS(int source)
   {
  
bool *visited = new bool[v];
for(int i = 0; i < v; i++)
visited[i] = false;

queue<int> q(v);
visited[source] = true;
q.enqueue(source) ;
  
while(!q.empty())
{
source = q.frontElement();
cout << source << " ";
q.dequeue();
for (int i = 0; i <v; ++i)
{
if (!visited[i]&&arr[source][i]==1)
{
visited[i] = true;
q.enqueue(i);
}
}
}
}
  
};

int main(){
   graph g(10);
   g.addEdge(0,1);
   g.addEdge(0,2);
   g.addEdge(0,3);
   g.addEdge(1,5);
   g.addEdge(2,4);
   g.addEdge(3,5);
   g.addEdge(3,4);
   g.addEdge(3,8);
   g.addEdge(4,5);
   g.addEdge(6,7);
   g.addEdge(6,8);
   g.addEdge(7,9);
   g.addEdge(8,9);
  
   cout<<"DFS\n";
   g.DFS(0);
   cout<<"\n\nBFS\n";
   g.BFS(0);
}

//sample output

C:Users IshuManish\Documents dfsbfs.exe DFS 1 5 3 4286 ? 9 FS 01 23 5 4 8 69 ? Process exited after 0.07008 seconds with return value0 Press any key to continue -- .