Depth-First Search Graph with Stack

//Trần Việt Anh 19:25 12/04/2020
#include<iostream>
#include<fstream>
#include<vector>
#include<stack>

using namespace std;

vector<vector<int>> graph(0);

//Load the graph from text
void LoadG() {
    ifstream inFile;
    inFile.open("dothi.txt");
    int n; inFile >> n;
    for (int i = 0; i < n; i++) {
        vector<int> line(n);
        for (int j = 0; j < n; j++)
            inFile >> line[j];
        graph.push_back(line);
    }
}

//Depth first search from starting node u (startNode)
void DFS_Stack(int startNode) {
    vector<int> visited(graph.size(), false);
    stack<int> s;
    s.push(startNode);
    while (s.size() != 0) {
        int node = s.top(); s.pop();
        visited[node] = true;
        cout << "Visited node " << node << endl;
        for (int i = 0; i < graph.size(); i++)
            if (graph[node][i] == 1 && !visited[i])
                s.push(i);
    }
}


int main() {
    LoadG();

    //Print the graph matrix for testing
    for (int i = 0 ; i < graph.size(); i++) {
        for (int j = 0; j < graph.size(); j++)
            cout << graph[i][j] << " ";
        cout << endl;
    }

    //Depth first search
    DFS_Stack(0);
}