fork download 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. // initialize a 51x51 vector with cell value of 0 for each cell
  5. vector<vector<int>> adjacencyMatrix(51, vector<int>(51, 0));
  6.  
  7. // initialize a vector with 51 empty rows
  8. vector<vector<int>> adjacencyList(51);
  9.  
  10. // Declare file stream so all functions can access it
  11. ifstream file("input.txt");
  12. int u, v;
  13.  
  14. void inputMatrix(int &nodes, int &edges);
  15. void inputList(int &nodes, int &edges);
  16. void printMatrix(int nodes);
  17. void printList(int nodes);
  18.  
  19. int main(){
  20.     int input, nodes, edges;
  21.  
  22.     cout << "Enter 1 or 2 based on your preference." << endl;
  23.     cout << "Option 1: If you want to store the graph to adjacency matrix." << endl;
  24.     cout << "Option 2: If you want to store the graph to adjacency list." << endl;
  25.     cout << "Enter your option (1/2): ";
  26.  
  27.     while (cin >> input){
  28.         if (input != 1 && input != 2){
  29.             cout << "Invalid Input!!! try again." << endl;
  30.             cout << "Enter your option (1/2): ";
  31.             continue;
  32.         }
  33.         break;
  34.     }
  35.     // Check if file can be opened
  36.     if (!file){
  37.         cout << "Error opening file!" << endl;
  38.         return 0;
  39.     }
  40.     // Read total number of nodes and edges from file
  41.     file >> nodes >> edges;
  42.  
  43.     if (input == 1){
  44.         inputMatrix(nodes, edges);
  45.         printMatrix(nodes);
  46.     }
  47.     else{
  48.         inputList(nodes, edges);
  49.         printList(nodes);
  50.     }
  51.        file.close();
  52.     return 0;
  53. }
  54.  
  55. void inputMatrix(int &nodes, int &edges){
  56. int count = 0;
  57.  // Read each edge (u, v) and update adjacency matrix
  58.     while (count < edges && file >> u >> v)
  59.     {
  60.         adjacencyMatrix[u][v] = 1;// edge from u to v
  61.         adjacencyMatrix[v][u] = 1;// edge from v to u
  62.         count++;
  63.     }
  64. }
  65.  
  66. void inputList(int &nodes, int &edges){
  67. int count = 0;
  68. // Read each edge (u, v) and store in adjacency list
  69. while (count < edges && file >> u >> v){
  70.         adjacencyList[u].push_back(v);
  71.         adjacencyList[v].push_back(u);
  72.         count++;
  73.     }
  74. }
  75. // Displays the adjacency matrix
  76. void printMatrix(int nodes){
  77.     cout << "\nAdjacency Matrix :\n";
  78.     for(auto rowIt= adjacencyMatrix.begin()+1;rowIt!= adjacencyMatrix.begin()+1+nodes;++rowIt){
  79.         for(auto colIt= rowIt->begin()+1;colIt!= rowIt->begin()+1+nodes;++colIt){
  80.             cout << *colIt << " ";
  81.         }
  82.         cout << endl;
  83.     }
  84. }
  85. // Displays the adjacency list
  86. void printList(int nodes){
  87.     cout << "\nAdjacency List:\n";
  88.      // Loop through each node and print its connections
  89.     for (int i = 1; i <= nodes; i++){
  90.         cout << "Node"<<" " << i<<" " << "connected to : ";
  91.         if (adjacencyList[i].empty()){
  92.             cout << "No connections";
  93.         }
  94.         else{
  95.             bool a = true; // for proper separator
  96.             for (int e : adjacencyList[i]){
  97.                 if (!a){
  98.                     cout << " , "; }// separator
  99.                 cout << e;
  100.                 a = false;
  101.             }
  102.         }
  103. cout << endl;
  104.     }
  105. }
  106.  
Success #stdin #stdout 0.01s 5288KB
comments (?)
stdin 
Standard input is empty
stdout 
Enter 1 or 2 based on your preference.
Option 1: If you want to store the graph to adjacency matrix.
Option 2: If you want to store the graph to adjacency list.
Enter your option (1/2): Error opening file!
https://ideone.com/fUNb9X
language:
C++14 (clang 8.0)
created:
4 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!