#include<iostream>

#include<stack>

using namespace std;

const static int INF = __INT_MAX__;

/*

A B

/ \ /

/ \ /

/ C------D

E /

\ /

\ /

F

*/

int matrix[6][6] = {{INF, INF, 1, INF, 1, INF},

{INF, INF, 1, INF, INF, INF},

{1, 1, INF, 1, INF, INF},

{INF, INF, 1, INF, INF, 1},

{1, INF, INF, INF, INF, 1},

{INF, INF, INF, 1, 1, INF}

};

int visited[6] = {0};

void DFS(stack<char>& s, char ch)

{

if (s.empty())

return;

cout << ch;

for (int i = 0; i < 6; i++)

{

if (matrix[ch - 'A'][i] == 1 && visited[i] == 0)

{

visited[i] = 1;

s.push('A' + i);

DFS(s, s.top());

}

}

s.pop();

}

int main(int argc, char const *argv[])

{

stack<char> s;

char begin = 'A';

cout << "DFS begin from A:\n";

s.push(begin);

visited[0] = 1;

DFS(s, s.top());

cout << endl;

return 0;

}