Cod sursa(job #2663590)

Utilizator Xutzu358Ignat Alex Xutzu358 Data 26 octombrie 2020 20:34:08
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <bits/stdc++.h>
using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

int n,m;
int oo = 2000000009;
int dist[50005];
vector < pair < int , int > > v[50005];
set < pair < int , int > > s;

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

void show() {
    for (int i=2;i<=n;i++) {
        if (dist[i]!=oo) {
            g << dist[i] << " ";
        }
        else {
            g << 0 << " ";
        }
    }
}

void infinity() {
    for (int i=1;i<=n;i++) {
        dist[i]=oo;
    }
}

void dijkstra() {
    dist[1]=0;
    s.insert(make_pair(0,1));
    while (s.empty()==0) {
        int nod = s.begin()->second;
        s.erase(s.begin());
        for (size_t i=0 ; i<v[nod].size() ; i++) {
            int nodtoviz = v[nod][i].first;
            int distance = v[nod][i].second;
            if (dist[nod] + distance < dist[nodtoviz]) {
                s.erase(make_pair(dist[nodtoviz],nodtoviz));
                dist[nodtoviz] = dist[nod] + distance;
                s.insert(make_pair(dist[nodtoviz],nodtoviz));
            }
        }
    }
}

int main()
{
    read();
    infinity();
    dijkstra();
    show();
    return 0;
}