Cod sursa(job #2073908)

Utilizator killer301Ioan Andrei Nicolae killer301 Data 23 noiembrie 2017 20:34:25
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.62 kb
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>

using namespace std;

const int NMAX = 50000;
const int INF = 2000000000;

int n;
bool vis[NMAX+5];
int dist[NMAX+5];
vector <pair <int, int> > graph[NMAX+5];

struct cmp
{
    bool operator() (const pair <int, int> a, const pair <int, int> b)
    {
        return a.second > b.second;
    }
};

void Dijkstra(int nod)
{
    priority_queue < pair <int, int> , vector < pair <int, int> >, cmp > q;
    dist[nod] = 0;
    q.push(pair <int, int> (nod, 0));
    while(!q.empty())
    {
        pair <int, int> top = q.top();
        q.pop();
        if(vis[top.first]) continue;
        vis[top.first] = true;
        for(int i=0; i<graph[top.first].size(); i++)
        {
            pair <int, int> New = graph[top.first][i];
            if(!vis[New.first])
            {
                if(dist[top.first] + New.second < dist[New.first])
                {
                    dist[New.first] = dist[top.first] + New.second;
                    q.push(pair <int, int> (New.first, dist[New.first]));
                }
            }
        }
    }
}

int main()
{
    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);
    int n, m;
    scanf("%d%d", &n, &m);
    for(int i=0; i<m; i++)
    {
        int x, y, c;
        scanf("%d%d%d", &x, &y, &c);
        graph[x].push_back(pair <int, int> (y, c));
    }
    for(int i=1; i<=n; i++)
        dist[i] = INF;
    Dijkstra(1);
    for(int i=2; i<=n; i++)
        printf("%d ", dist[i] == INF ? 0 : dist[i]);
    printf("\n");
    return 0;
}