Algoritmul Roy-Warshall:Exista drum intre nodul x si nodul y?

#include <iostream>#include <conio.h>
using namespace std;
int main()
{
int n,i,a[100][100],j,k,x,y;
cout<<"n=";cin>>n;
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
{cout<<"a["<<i<<"]["<<j<<"]=";
cin>>a[i][j];
}
for(k=1;k<=n;k++)
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
if(a[i][j]==0&& i!=k&&j!=k)
a[i][j]=a[i][k]*a[k][j];
cout<<"Nodul initial:";cin>>x;
cout<<"Nodul final:";cin>>y;
if(a[x][y]==1)
cout<<"Exista drum intre nodul "<<x<<" si nodul "<<y<<".";
else
cout<<"NU exista drum intre nodul "<<x<<" si nodul "<<y<<".";
getch();
return 0;
}

CONEXITATE IN GRAFURI NEORIENTATE

#include<fstream>
using namespace std;
int k,m,n,x[100],a[100][100],p[100];
 
fstream f("date.in",ios::in);
fstream g("date.out",ios::out);
 
void citire()
 {int x,y;
  f>>n>>m;
  for(int i=1;i<=m;i++)
   {f>>x>>y;
    a[x][y]=1;
    a[y][x]=1;
   }
 }
void rw()
 {int i, j, k;
  for(k=1;k<=n;k++)
   for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
   if(i!=j)
   if(a[i][j]==0)
   a[i][j]=a[i][k]*a[k][j];
 }
 void afis()
  {for(int i=1;i<=n;i++)
    if(!p[i])
    { g<<i<<" ";
      p[i]=1;
      for(int j=1;j<=n;j++)
         if(a[i][j]) { g<<j<<" "; p[j]=1;}
      g<<endl;
   }
  }
 
int main()
  {citire();
   rw();
   afis();
   f.close();
   g.close();
   return 0;
  }
 
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