Probleme de informatica - enunturi si rezolvari

Se da un graf orientat cu n varfuri si m arce avand arcele etichetate cu costuri numere naturale.
Se citesc apoi doua varfuri x si y. Afisati drumul de cost minim de la varful x la varful x trecand prin varful y, precum si costul acestui drum.
Exemplu:
date.in
12 21 (n,m)
1 2 20 (arcele si costurile)
1 3 35
1 7 20
2 4 30
3 4 40
3 6 40
3 8 80
4 5 25
5 6 5
6 8 30
6 9 10
7 8 15
7 11 100
8 9 40
8 10 30
8 11 35
9 10 30
10 12 25
11 12 10
10 5 15
5 1 10
1 10 (x,y)
date.out
1 7 8 10 5 1
90

#include<fstream>
using namespace std;
const int inf=100000;
int c[200][200],d[200],p[200],n,m,x,y,t[200];
ifstream f("date.in");
ofstream g("date.out");

void citire()
{ int i,j,k,cost;
  f>>n>>m;
  for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
      if(i==j) c[i][j]=0;
      else c[i][j]=inf;
  for(k=1;k<=m;k++)
    { f>>i>>j>>cost;
      c[i][j]=cost;
    }
  f>>x>>y;
}

void dijkstra(int s)
{ int i,j,k,minn;
  for(i=1;i<=n;i++)
     {
         d[i]=c[s][i];
         if(i!=s && d[i]!=inf) t[i]=s;
         else t[i]=0;
         p[i]=0;
     }

  p[s]=1;
  for(k=1;k<n;k++)
   { minn=inf;
     for(i=1;i<=n;i++)
       if(!p[i] && d[i]<minn)
                 { minn=d[i]; j=i;
			     }
     for(i=1;i<=n;i++)
       if(!p[i] && d[i]>d[j]+c[j][i])
            { d[i]=d[j]+c[j][i];
              t[i]=j;
            }
     p[j]=1;
   }
}

void drum(int i)
{ if(t[i]) drum(t[i]);
  g<<i<<" ";
}

int main()
 { int i,v;
   citire();
   dijkstra(x);
   v=d[y];
   drum(t[y]);
   dijkstra(y);
   v=v+d[x];
   drum(x);
   g<<endl<<v;
   f.close();
   g.close();
   return 0;
}

25 apr 2024

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