Cod sursa(job #2030237)

Utilizator LurchssLaurentiu Duma Lurchss Data 1 octombrie 2017 12:43:49
Problema Algoritmul Bellman-Ford Scor 5
Compilator cpp Status done
Runda Arhiva educationala Marime 1.5 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <bitset>
#include <string.h>

#define inf 0x3f3f3f3f
#define NMAX 5001
using namespace std;

int n,m;
vector< pair<int,int > > g[NMAX];
queue<int> q;
bitset<NMAX> viz;
int d[NMAX]; ///distance
int counter[NMAX];

void citire()
{
    scanf("%d %d",&n,&m);

    int x,y,c;
    for(int i=0;i<m;i++)
    {
        scanf("%d %d %d",&x,&y,&c);
        g[x].push_back(make_pair(y,c));
    }
}

void bellman()
{
    memset(d,inf,sizeof(d));
    q.push(1);
    d[1] = 0;

    while(!q.empty())
    {
        int top = q.front();
        q.pop();
        viz[top] = 0;

        for( vector<pair<int,int> >::iterator it = g[top].begin(); it!=g[top].end(); it++)
        {
            if( d[(*it).first] > d[top] + (*it).second )
            {
                if(++counter[top] == n)
                    {
                        printf("Ciclu negativ!");
                        return;
                    }
                if(!viz[(*it).first])
                {
                    q.push((*it).first);
                    viz[(*it).first] = 1;
                    d[(*it).first] = d[top] + (*it).second;
                }
            }
        }
    }
}

void afisare()
{
    for(int i=2;i<=n;i++)
        printf("%d ",d[i]);
}
int main()
{
    freopen("bellmanford.in","r",stdin);
    freopen("bellmanford.out","w",stdout);

    citire();
    bellman();
    afisare();

    return 0;
}