C++ implements relational classes for discrete mathematics and supports transitive closure operations

  1 #include <vector>
  2 #include <cassert>
  3 #include <iostream>
  4 using namespace std;
  5 class Graph{
  6 private:
  7     int n;
  8     int** graph;
  9 public:
 10     Graph(int n){
 11         this->n = n;
 12         graph = new int*[n];
 13         for(int i=0;i<n;i++)
 14             graph[i] = new int[n];
 15         for(int i=0;i<n;i++)
 16             for(int j=0;j<n;j++)
 17                 graph[i][j] = 0;
 18     }
 19     void addEdge(int a,int b){
 20         assert(a>0&&a<=n);
 21         assert(b>0&&b<=n);
 22         if(connected(a-1,b-1))
 23             return;
 24         graph[a-1][b-1] = 1;
 25     }
 26     void removeEdge(int a,int b){
 27         assert(a>0&&a<=n);
 28         assert(b>0&&b<=n);
 29         if(!connected(a,b))
 30             return;
 31         graph[a-1][b-1] = 0;
 32     }
 33     bool connected(int a,int b){
 34         return graph[a][b]==1;
 35     }
 36     void plus(int a1,int b1,int a2,int b2){
 37         if(graph[a1][b1]==0)
 38             graph[a1][b1]+=graph[a2][b2];
 39         else
 40             return;
 41     }
 42     void display(){
 43         cout<<"Matrix Form:"<<endl;
 44         for(int i=0;i<n;i++){
 45             for(int j = 0;j<n;j++)
 46                 cout<<graph[i][j]<<" ";
 47             cout<<endl;
 48         }
 49         cout<<"Front: ";
 50         for(int i=0;i<n;i++)
 51             for(int j=0;j<n;j++){
 52                 if(graph[i][j])
 53                     cout<<"<"<<i+1<<","<<j+1<<">  ";
 54         }
 55         cout<<endl;
 56     }
 57 };
 58 
 59 class RelationShip{
 60 private:
 61     bool print;
 62     int num_points;
 63     Graph graph;
 64 public:
 65     RelationShip(int num):graph(num){
 66         print = true;
 67         this->num_points = num;
 68     }
 69 
 70     void add_RS(int a,int b){
 71         graph.addEdge(a,b);
 72     }
 73 
 74     void remove_RS(int a,int b){
 75         graph.removeEdge(a,b);
 76     }
 77  
78      void transfer(){ // Use the matrix as a transitive closure operation 
79          for ( int i = 0 ;i<num_points;i++ ){
 80              for ( int j = 0 ;j<num_points;j++ ){
 81                  if (graph.connected(j,i)){
 82                      for ( int k = 0 ;k<num_points;k++ )
 83                          graph.plus(j,k,i,k);
 84                  }
 85              }
 86          }
 87         print = true ;
 88      }
 89  
90      void show(){
 91          graph.display();
 92      }
 93  };
 94  
95  int main(){
 96      cout<< " Enter the number of elements you want: " << endl ;
 97      int n;
 98      while (cin>> n){
 99          RelationShip op = RelationShip(n);
 100          int num;
 101          cout<< " How many pairs of relations do you want to connect? " <<endl;
 102          cin>> num;
 103          while (num-- ){
 104              cout<< " Please enter any pair between [1, " <<n<< " ] " << endl;
 105 int a ,b;
 106              cin>>a>> b;
 107             op.add_RS(a,b);
 108         }
 109          cout<< " Do you want to perform transitive closure operations? (yes or no) " << endl;
 110 string s;
 111          cin>> s;
112if                                 (s=="yes")
113             op.transfer();
114         op.show();
115     }
116 }