Cod sursa(job #2338736)

Utilizator refugiatBoni Daniel Stefan refugiat Data 7 februarie 2019 19:14:57
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define mkp make_pair
#define x first
#define y second
#define NMAX 50005
#define inf 2000000000
using namespace std;
ifstream si("bellmanford.in");
ofstream so("bellmanford.out");
vector< pair<int,int> > v[NMAX];
queue<int> q;
int minn[NMAX];
int ap[NMAX],n;
bool bf() {
    q.push(1);
    int l, nod;
    while(!q.empty()) {
        nod=q.front();
        ap[nod]++;
        if(ap[nod]>n)
            return 0;
        q.pop();
        l=v[nod].size();
        for(int i=0; i<l; ++i) {
            if(minn[v[nod][i].x]>minn[nod]+v[nod][i].y) {
                minn[v[nod][i].x]=minn[nod]+v[nod][i].y;
                q.push(v[nod][i].x);
            }
        }
    }
    return 1;
}
int main() {
    int m;
    si>>n>>m;
    int a,b,c;
    for(int i=0;i<m;++i) {
        si>>a>>b>>c;
        v[a].push_back(mkp(b,c));
    }
    for(int i=2;i<=n;++i)
        minn[i]=inf;
    if(!bf())
        so<<"Ciclu negativ!";
    else {
        for(int i=2;i<=n;++i) {
            if(minn[i]==inf)
                so<<0<<' ';
            else
                so<<minn[i]<<' ';
        }
    }
    return 0;
}