Cod sursa(job #2908210)

Utilizator lolotbogdanLolot Stefan-Bogdan lolotbogdan Data 2 iunie 2022 08:34:46
Problema Floyd-Warshall/Roy-Floyd Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.35 kb
#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

#define INF 100000

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

int n; // nr de noduri
vector<vector<int>>d; // matricea costului minim al unui drum de la i la j care are vf intermediare in {1, ..., k}
vector<vector<int>>p; // predecesorul unui nod j pe drumul minim curent gasit de la i la j care are vf intermediare {1, ..., k}

void floydWarshall(){

    for(int k = 1; k <= n; k++)
        for(int i = 1; i <= n; i++)
            for(int j = 1; j <= n; j++)
                if(d[i][j] > d[i][k] + d[k][j]){
                    d[i][j] = d[i][k] + d[k][j];
                    p[i][j] = i;
                }
}

int main()
{

    f >> n;

    d.resize(n + 1, vector<int>(n + 1, INF));
    p.resize(n + 1, vector<int>(n + 1, 0));


    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++){
            int cost;

            f >> cost;

            d[i][j] = cost;
            p[i][j] = i;
        }
    }

    for(int i = 1; i <= n; i++)
        d[i][i] = p[i][i] = 0;

    floydWarshall();

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

    return 0;
}