Cod sursa(job #1792103)

Utilizator moise_alexandruMoise Alexandru moise_alexandru Data 30 octombrie 2016 00:37:58
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <bits/stdc++.h>
using namespace std;
const int INF = (1 << 30);
ifstream in("dijkstra.in");
ofstream out("dijkstra.out");
const int maxn = 50005;
class cmp {
public:
    bool operator()( pair<int, int> a, pair<int, int> b ) {
        return a.second > b.second;
    }
}; priority_queue<pair<int, int>, vector< pair<int, int> >, cmp> pq;

vector <pair <int, int> > g[maxn];
int dp[maxn];

int main( ) {

    int n, m;
    in >> n >> m;

    for( int i = 1; i <= m; i ++ ) {
        int x, y, z;
        in >> x >> y >> z;

        g[x].push_back( make_pair(y, z) );
        g[y].push_back( make_pair(x, z) );
    }

    fill( dp + 1, dp + n + 1, INF );
    dp[1] = 0; pq.push( make_pair(1, 0) );

    while( !pq.empty() ) {
        pair<int, int> p = pq.top(); pq.pop();

        for(auto it : g[p.first])
        {
            int nod = it.first, cost = it.second;
            if(dp[nod] > dp[p.first] + cost)
            {
                dp[nod] = dp[p.first] + cost;
                pq.push(make_pair(nod, dp[nod]));
            }
        }
    }
    for(int i = 2; i <= n; i++)
    {
        if(dp[i] != INF)
            out << dp[i];
        else
            out << 0;
        out << " ";
    }
    return 0;
}