Graph Implemetation and DFS and BFS

Graph_BFS_DFS.cpp

/**
 
coded by - pathakcodes  //revamped
**/


#include<bits/stdc++.h>
using namespace std ;
map<int, vector<int>> graph ;
map<int, bool> visited ;
map<int, int> level ;

void dfs(int s){
    cout << s << endl;
    visited[s] = true ;
    for(auto list : graph[s]){
        if(visited[list] == false)
            dfs(list);
    }
}

void bfs(int s ){
    queue<int> q ;
    q.push(s);
    level[s] = 0 ;
    int prevLevel = 0, curLevel = 0 ;
    
    while(!q.empty()){
        int top = q.front() ;
        visited[top] = true ;
    
        q.pop();
        
        for(auto list:graph[top]){
            if(visited[list] == false){
            level[list] = level[top]+1;
            q.push(list);
            }
        }
        curLevel = level[top] ;
        if(prevLevel != curLevel){
            cout << endl ;
            prevLevel = curLevel ;
        }
        cout << top << " " ;
        
    }
}

int main(){

    int n ;
    cin >> n ;
    
    for(int i = 0 ; i < n ; i++){
        
        int start, end ;
        cin >> start >> end ;
        
        graph[start].push_back(end);
        graph[end].push_back(start);
        
    }
    
    // dfs(1) ;
    bfs(1) ;

    
    

}