#include <iostream>

#include <vector>

using namespace std;

vector<vector<int>> adj;

vector<bool> visited;

void dfs(int from) {

cout << endl << "--dfs(" << from << ") is called--" << endl;

cout << " so visited " << from <<" will be 'true'" << endl;

visited[from] = true;

for (size_t i = 0; i < adj[from].size(); ++i) {

int to = adj[from][i];

cout << " from : "<<from<<"/ to : " << to << endl;

if (!visited[to]) {

cout << " dfs(" << to << ") is called" << endl;

dfs(to);

}

}

}

void dfsAll() {

visited = vector<bool>(adj.size(), false);

for (size_t i = 0; i < adj.size(); ++i) {

if (!visited[i]) {

cout << endl << "-dfsAll(" << i << ") is called-" << endl;

dfs(i);

}

else {

cout << "node " << i << " is already visited" << endl;

}

}

}

void showAdj(vector<vector<int>> adjacent) {

for (size_t i = 0; i < adjacent.size(); ++i) {

for (size_t j = 0; j < adj[i].size(); ++j) {

if (adjacent[i][j] != NULL)

{

cout << i << " -> " << adjacent[i][j] << endl;

}

}

}

}

int main() {

adj.resize(7);

visited.resize(7);

adj[0].push_back(1);

adj[0].push_back(2);

adj[1].push_back(3);

adj[1].push_back(4);

adj[5].push_back(6);

showAdj(adj);

dfsAll();

return 0;

}