Cod sursa(job #2174081)

Utilizator andysoloAndrei Solo andysolo Data 16 martie 2018 10:41:30
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 kb
#include <cstdio>
#include <iostream>
#include <queue>
#include <climits>
#define NMAX 50000+5
#define mp make_pair
#define p pair<int,int>
#define f first
#define s second

using namespace std;

int N,M;
bool c[NMAX];
long long D[NMAX];
vector <p> leg[NMAX];
p X;
struct comp
{
    bool operator()(int x,int y)
    {
        return D[x]>D[y];
    }
};
// priority_queue<int, vector<int>, comp>q;
priority_queue<pair<int,int>,vector<pair<int,int> >,greater<pair<int,int> > >q;
void dijkstra(int nodi)
{
    for(int i=1; i<=N; i++)
        D[i]=INT_MAX;

    D[nodi]=0;
    q.push({0,nodi});

    while(!q.empty())
    {
        X=q.top();
        int cost=X.f;
        int poz=X.s;
        q.pop();

        for(int i=0; i<leg[poz].size(); ++i)
            if(D[leg[poz][i].first]>cost+leg[poz][i].second)
            {
                D[leg[poz][i].first]=cost+leg[poz][i].second;
                q.push({D[leg[poz][i].first],leg[poz][i].first});
            }
    }
}

int main()
{
    freopen("dijkstra.in","r",stdin);
    freopen("dijkstra.out","w",stdout);
    scanf("%d %d",&N,&M);

    for(int i=1; i<=M; i++)
    {
        int x,y,z;
        scanf("%d %d %d",&x,&y,&z);
        leg[x].push_back(mp(y,z));
    }

    dijkstra(1);

    for(int i=2;i<=N;i++)
    {
        if(D[i]==INT_MAX)
            printf("0 ");
        else
        printf("%d ",D[i]);
    }

    return 0;
}