Cod sursa(job #1756754)

Utilizator din99danyMatei Daniel din99dany Data 13 septembrie 2016 16:31:25
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.31 kb
#include <cstdio>
#include <queue>
#include <vector>
using namespace std;

#define NMAX 50005
#define INFI 0x3f3f3f3f
vector < pair < int, int > > v[ NMAX ];
queue < int > Q;

int numara[ NMAX ],
      dist[ NMAX ],
      in_queue[ NMAX ];

int main()
{

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

    int n, m, i, j, x, y, c, nod;

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

    for( i = 2; i <= n; ++i ) dist[ i ] = INFI;

    vector < pair < int, int > > :: iterator it;
    Q.push( 1 );

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

        if( ++numara[ nod ] >= n ){
            printf("Ciclu negativ!\n");
            return 0;
        }

        for( it = v[ nod ].begin(); it != v[ nod ].end(); ++it ){
            if( dist[ it -> second ] > dist[ nod ] + it -> first ){
                dist[ it -> second ] = dist[ nod ] + it -> first;
                if( !in_queue[ it -> second ] ){
                    Q.push( it -> second );
                    in_queue[ it -> second ] = 1;
                }
            }
        }
    }


    for( i = 2; i <= n; ++i ) printf("%d ",dist[ i ]);


    return 0;
}