Cod sursa(job #3199007)

Utilizator ililogIlinca ililog Data 31 ianuarie 2024 12:03:58
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.23 kb
using namespace std;
#include<iostream>
#include<fstream>
#include<vector>
#include<queue>

ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");

#define NMAX 50005
#define INF 1e9

struct arc{
    int vf, c;
};

vector<arc> G[NMAX];
int cmin[NMAX], nr[NMAX], start = 1;
bool circuitneg;
int n, m;
queue<int> Q;

int main() {
    fin >> n >> m;
    for (int i = 1; i<=m; i++) {
        int x, y, cost;
        fin >> x >> y >> cost;
        arc A = {y, cost};
        G[x].push_back(A);
    }

    for (int i = 1; i<=n; i++) {
        cmin[i] = INF;
    }
    cmin[start] = 0;
    Q.push(start);

    while (!Q.empty() && !circuitneg) {

        int x = Q.front();
        Q.pop();

        for (unsigned int i = 0; i<G[x].size(); i++) {
            int y = G[x][i].vf, cost = G[x][i].c;
            if (cmin[y] > cmin[x] + cost) {
                cmin[y] = cmin[x] + cost;
                nr[y]++;
                if (nr[y] == n) circuitneg = 1;
                else Q.push(y);
            }
        }

    }

    if (circuitneg) {
        fout << "Ciclu negativ!";
    } else {
        for (int i = 2; i<=n; i++) {
            fout << cmin[i] << " ";
        }
    }

    return 0;
}