Cod sursa(job #416551)

Utilizator ucc_5Usurelu Catalin ucc_5 Data 12 martie 2010 22:10:04
Problema Floyd-Warshall/Roy-Floyd Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
#define NMAX 110
using namespace std;
ifstream f("royfloyd.in");
ofstream g("royfloyd.out");

int a[NMAX][NMAX],n;

void citire ()
{
  f>>n;
  for (int i=1; i<=n; i++)
	for (int j=1; j<=n; j++)
	  f>>a[i][j];
}


void RF ()
{
  for (int k=1; k<=n; k++)
	for (int i=1; i<=n; i++)
	  for (int j=1; j<=n; j++)
		if (a[i][k] && a[k][j] && (a[i][j]>a[i][k]+a[k][j] || (!a[i][j] && i!=j))) a[i][j]=a[i][k]+a[k][j];
//sau a[i][j]=min(a[i][j],a[i][k]+a[k][j]) cu conditia ca daca nu exista arc de la x la y (la citire) atunci a[x][y]=inf
//in cazul in care nu exista drum de la x la y in urma executiei algoritului a[i][j] va fi egal cu 0 pentru ca la un moment dat i=k=j
//deci a[i][k]=0 si a[k][j]=0
}

void afisare ()
{
  for (int i=1; i<=n; i++)
  {
	for (int j=1; j<=n; j++)
	  g<<a[i][j]<<" ";
	g<<'\n';
  }
}

int main ()
{
  citire ();
  RF ();
  afisare ();
  return 0;
}