Cod sursa(job #2091234)

Utilizator infomaxInfomax infomax Data 19 decembrie 2017 12:39:38
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>
#include <vector>
#include <bitset>
#include <queue>

#define f first
#define s second

using namespace std;

ifstream F("bellmanford.in");
ofstream G("bellmanford.out");

int n, m, c, x, y,d[50005], knod[50005];
const int inf = 1 << 30;
queue<int> q;
vector<pair<int, int> > a[50005];
bitset<50006>inq;

int main()
{
    F >> n >> m;
    for( int i = 1; i <= m; ++ i )
    {
        F >> x >> y >> c;
        a[x].push_back({y, c});
    }
    for( int i = 2; i <= n; ++ i ) d[ i ] = inf;
    q.push(1);inq[1] = 1;
    vector<pair<int, int> > :: iterator it;
    while(!q.empty())
    {
        x = q.front();
        q.pop();
        inq[x] = 0;
        for( it = a[x].begin(); it != a[x].end(); ++ it )
            if( d[ (*it).f ] > d[ x ] + (*it).s )
            {
                d[ (*it).f ] = d[ x ] + (*it).s;
                if(!inq[(*it).f]) q.push((*it).f), inq[(*it).f] = 1;
                if(++knod[(*it).f] > n)
                {
                    G << "Ciclu negativ!";
                    return 0;
                }
            }
    }
    for( int i = 2; i <= n; ++ i )
        G << d[i] << " ";
    return 0;
}