Breadth First Search(BFS) of a Graph in CPP

bfs.cpp

#include <iostream>
using namespace std;

// This is Implementation of Queue

struct Node {
    int data;
    struct Node *next;
}*front=NULL,*rear=NULL;

void enqueue(int ele){
    struct Node *temp;
    temp = new Node;
    temp->data = ele;
    temp->next = NULL;
    if(front==NULL){
        front=rear=temp;
    }else{
        rear->next = temp;
        rear=temp;
    }
}

int dequeue(){
    if(front==NULL){
        return 0;
    }
    struct Node *p=front;
    int x;
    x=front->data;
    front = front->next;
    delete p;
    return x;
}

int isempty(){
    return front==NULL;
}

// Queue implementation ends here

void BFS(int A[][7],int start, int n){
    int visited[7]={0};
    int i=start,j;
    cout << i << " ";
    visited[i] = 1;
    enqueue(i);
    while(!isempty()){
        j = dequeue();
        for(int x=1;x<n;x++){
            if(A[j][x]==1 && visited[x]!=1){
                cout << x << " ";
                visited[x] = 1;
                enqueue(x);
            }
        }
    }
}

int main(){
    int start=1;
    int size=7;
  
    int A[7][7]={{0,0,0,0,0,0,0},
               {0,0,1,1,0,0,0},
               {0,1,0,0,1,0,0},
               {0,1,0,0,1,0,0},
               {0,0,1,1,0,1,1},
               {0,0,0,0,1,0,0},
               {0,0,0,0,1,0,0}};
  
    BFS(A,start,size);
    
}