Cod sursa(job #1402095)

Utilizator badea_adi1999Badea Adrian Catalin badea_adi1999 Data 26 martie 2015 12:26:02
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.21 kb
//Algritmul lui dijkstra cu heapuri stl
//O(M*log(n))
#include <fstream>
#include <queue>
#include <vector>
#include <bitset>
#define inf 1<<30
#define nmax 50005
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
int n,m,d[nmax];
vector <pair <int,int > > v[nmax];
vector <pair <int,int > > :: iterator it;
priority_queue<pair <int, int>, vector <pair <int,int > > , greater <pair <int ,int > > > heap;
bitset <nmax> uz;

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

    d[1]=0;
    for (i=2;i<=n;i++)
        d[i]=inf;
    heap.push(make_pair(0,1));

    while (!heap.empty()) {

        x=heap.top().second;
        heap.pop();
        if (uz[x]==1)
            continue;
        uz[x]=1;

        for (it=v[x].begin();it!=v[x].end();it++) {
            y=it->first;
            z=it->second;
            if (d[y]>d[x]+z) {
                d[y]=d[x]+z;
                heap.push(make_pair(d[y],y));
            }
        }
    }
    for (i=2;i<=n;i++)
        if (d[i]!=inf)
            g<<d[i]<<' ';
        else
            g<<"0 ";
    return 0;
}