Cod sursa(job #3199689)

Utilizator gabriela15Popescu Gabriela Irina gabriela15 Data 2 februarie 2024 15:38:43
Problema Floyd-Warshall/Roy-Floyd Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>

using namespace std;

const int INF=9999999; ///+infinit

int n, m,
    C[101][101]; ///matricea costurilor minime

ifstream f("royfloyd.in");
ofstream g("royfloyd.out");

void init()
{
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<i; j++)
            C[i][j]=C[j][i]=INF;
    }
}

void citire()
{
    int x, y, c;
    f >> n >> m;
    init();
    for(int i=1; i<=m; i++)
    {
        f >> x >> y >> c;
        C[x][y]=c;
    }
}

void Roy_Floyd() ///complexitate O(n^3)
{
    int cost;
    for(int k=1; k<=n; k++)
        for(int i=1; i<=n; i++)
            for(int j=1; j<=n; j++)
            {
                cost=C[i][k]+C[k][j];
                if(cost<C[i][j])
                    C[i][j]=cost;
            }
}

/**
Se afiseazaz matricea costurilor minime:
-costul minim al unui drum de la i la j daca exista
- -1 in caz contrat
**/

void afis()
{
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=n; j++)
            if(C[i][j]==INF)
                g << "0 ";
            else
                g << C[i][j] << ' ';
        g << '\n';
    }
}

int main()
{
    citire();
    Roy_Floyd();
    afis();
    f.close();
    g.close();
    return 0;
}