dfs_iterative.cpp

#include <bits/stdc++.h>
using namespace std;
std::vector<int> v[100];
std::vector<int>::iterator it;
stack<int> st;
bool visited[100];
void initalize(){
      for(int i=0;i<100;i++)
      	visited[i]=false;
}
void dfs_iterative(int s){
      st.push(s);
      visited[s]=true;
      while( !st.empty() ){
        int x=st.top();
        cout<<x<<" ";
        st.pop();
        for(int j=0;j<v[x].size();j++){
            if(!visited[v[x][j]]){
                st.push(v[x][j]);
                visited[v[x][j]]=true;
            }
        }
    }
}
int main(int argc, char const *argv[])
{
    ios_base::sync_with_stdio(false);
    int nodes,edges,x,y;
    cin>>nodes>>edges;
    for(int i=0;i<edges;i++){
    	cin>>x>>y;
    	//undirected graph
    	v[x].push_back(y);
    	v[y].push_back(x);
    }
    for(int i=1;i<=nodes;i++){
    	cout<<"Adjacency list of node "<<i<<" is ";
    	for(int j=0;j<v[i].size();j++){
    		if(j == v[i].size()-1 )    cout<<v[i][j]<<"\n";
    		else cout<<v[i][j]<<"-->";
    	}
    }
    initalize();
    cout<<"Depth first search of graph is ";
    for(int i=1;i<=nodes;i++){
        if(!visited[i]){
            dfs_iterative(i);
        }
    }
    return 0;
}