Cod sursa(job #2425564)

Utilizator catu_bogdan_99Catu Bogdan catu_bogdan_99 Data 24 mai 2019 21:40:14
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.52 kb
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;

const int INFI = 0X3F3F3F;
const int NMAX = 50001;

int Cnt[ NMAX ],
    D[ NMAX ],
    InQ[ NMAX ];

struct Muchie {
    int nod, cost;
};

vector < Muchie > V[ NMAX ];

bool Bellman_Ford ( int start, int n ) {

    int i, j;
    queue < int > Q;

    for ( int i = 0; i <= n; ++i ) {
        D[ i ] = INFI;
    }

    Q.push( start );
    D[ start ] = 0;

    while ( !Q.empty() ) {
        int nod = Q.front();
        Q.pop();
        InQ[ nod ] = 0;

        if ( Cnt[ nod ] > n ) {
            return false;
        }
        Cnt[ nod ]++;

        for ( i = 0; i < V[ nod ].size(); ++i ) {
            int fiu = V[ nod ][ i ].nod;
            int cost = V[ nod ][ i ].cost;
            if ( D[ fiu ] > D[ nod ] + cost ) {
                D[ fiu ] = D[ nod ] + cost;
                if ( !InQ[ fiu ] ) {
                    Q.push( fiu );
                    InQ[ fiu ] = 1;
                }
            }
        }
    }

    return true;

}

int main () {

    freopen( "bellmanford.in", "r", stdin );
    freopen( "bellmanford.out", "w", stdout );


    int n, m;
    int x, y, c;

    scanf( "%d%d", &n,&m );
    while ( m-- ) {
        scanf( "%d%d%d", &x,&y,&c );
        V[ x ].push_back( { y, c } );
    }

    if ( !Bellman_Ford( 1, n ) ) {
        printf("Ciclu negativ!");
    } else {
        for ( int i = 2; i <= n; ++i )
            printf( "%d ", D[ i ] );
    }

    return 0;
}