Cod sursa(job #2846500)

Utilizator MenelausSontea Vladimir Menelaus Data 9 februarie 2022 11:50:13
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <vector>
#include <fstream>
#include <set>
#include <queue>

std::ifstream in("dijkstra.in");
std::ofstream out("dijkstra.out");

const int N=50000;
const int M=250000;
const int INF=2000000000;

struct muchie
{
    int from;
    int to;
    int cost;
};

bool marked[N+1];
int dist[N+1];
std::vector<int> v[N+1];
muchie edge[M+1];

bool compare(int a, int b)
{
    return v[a]<v[b];
}

std::priority_queue<int, std::vector<int>, decltype(&compare)> q(&compare);

void Dijkstra()
{
    dist[1]=0;
    q.push(1);

    while(!q.empty())
    {
        int curr=q.top();
        q.pop();

        if(marked[curr]) continue;

        for(int l : v[curr])
        {
            int to=edge[l].to;

            if(dist[curr]+edge[l].cost<dist[to])
            {
                dist[to]=dist[curr]+edge[l].cost;
                q.push(to);
            }
        }

        marked[curr]=1;
    }
}

int n, m;

int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>edge[i].from>>edge[i].to>>edge[i].cost;
        v[edge[i].from].push_back(i);
    }

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

    Dijkstra();

    for(int i=2; i<=n; i++)
    {
        if(dist[i]-INF) out<<dist[i]<<" ";
        else out<<0<<" ";
    }
}