Cod sursa(job #1284169)

Utilizator PetrutiuPaulPetrutiu Paul Gabriel PetrutiuPaul Data 6 decembrie 2014 12:14:41
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 2.06 kb
/*#include <iostream>
#include <fstream>
#include <set>
#include <vector>

using namespace std;

    ifstream fin("dijkstra.in");
    ofstream fout("dijkstra.out");

vector<int> v[50100],c[50100];
set<pair< int, int> >s;
int d[50100],n,m,inf=10000000000;

void dijkstra()
{
    int x,val;
    for(int i=2;i<=n;i++)d[i]=inf;
    s.insert(make_pair(0,1));
    while(s.size()>0)
    {
        val=(*s.begin()).first;
        x=(*s.begin()).second;
        s.erase(*s.begin());
        for(int i=0;i<v[x].size();i++)
        {
            if(d[ v[x][i]] > c[x][i]+val)
            {
                d[v[x][i]]=c[x][i]+val;
                s.insert(make_pair(d[v[x][i]],v[x][i]));
            }
        }
    }
}


int main()
{
    int x,y,z;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>z;
        v[x].push_back(y);
        c[x].push_back(z);
    }

    dijkstra();

    for(int i=2;i<=n;i++)
    {
        if(d[i]==inf)fout<<0<<' ';
        else fout<<d[i]<<' ';
    }
}*/

#include <cstdio>
#include <cstring>
#include <set>
#include <vector>
using namespace std;

#define pb push_back
#define mp make_pair
#define MAXN 50100
#define INF 1000000000

int N, M, d[MAXN]; vector<int> G[MAXN], C[MAXN];
set< pair<int, int> > T;

void solve(void)
{
    int i, j, k, val, x;

    for(i = 2; i <= N; i++) d[i] = INF;
    T.insert( mp(0, 1) );

    while( T.size() > 0 )
    {
        val = (*T.begin()).first, x = (*T.begin()).second;
        T.erase(*T.begin());
        for(i = 0; i < G[x].size(); i++)
         if(d[ G[x][i] ] > val + C[x][i] )
            d[ G[x][i] ] = val + C[x][i], T.insert(mp(d[G[x][i]],G[x][i]));
    }
}

int main(void)
{
    freopen("dijkstra.in", "rt", stdin);
    freopen("dijkstra.out", "wt", stdout);

    int i, a, b, c;

    scanf("%d %d\n", &N, &M);

    for(i = 1; i <= M; i++)
        scanf("%d %d %d\n", &a, &b, &c), G[a].pb(b), C[a].pb(c);

    solve();

    for(i = 2; i <= N; i++)
        printf("%d ", d[i] == INF ? 0 : d[i]);

    return 0;
}