Cod sursa(job #2353593)

Utilizator maria_sinteaMaria Sintea maria_sintea Data 24 februarie 2019 13:22:39
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.43 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#define inf 0x3f3f3f3f
#define N 250005

using namespace std;

int n, m, cost[N], viz[N];
struct cmp
{
    bool operator()(int a, int b)
    {
        return cost[a]>cost[b];
    }
};
vector <pair <int, int> > g[N];
vector <pair <int, int> > ::iterator it;
priority_queue <int, vector<int>, cmp> heap;

void citire()
{
    scanf("%d %d\n", &n, &m);
    for(int i=0;i<m;i++)
    {
        cost[i]=inf;
        int x, y, c;
        scanf("%d %d %d\n", &x, &y, &c);
        g[x].push_back({y, c});
    }
}

void parcurg(int nod)
{
    for(it=g[nod].begin();it!=g[nod].end();it++)
        if(cost[it->first]>cost[nod]+it->second)
        {
            cost[it->first]=cost[nod]+it->second;
            if(!viz[it->first])
            {
                viz[it->first]=1;
                heap.push(it->first);
            }
        }
}

void dijkstra()
{
    cost[1]=0;
    heap.push(1);
    while(!heap.empty())
    {
        int nod=heap.top();
        heap.pop();
        viz[nod]=0;
        parcurg(nod);
    }
}

void afisare()
{
    for(int i=2;i<=n;i++)
    {
        if(cost[i]==inf)
            cost[i]=0;
        printf("%d ", cost[i]);
    }
}

int main()
{
    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);

    citire();
    dijkstra();
    afisare();
    return 0;
}