Cod sursa(job #2004217)

Utilizator MaligMamaliga cu smantana Malig Data 25 iulie 2017 12:08:31
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.37 kb
#include <iostream>
#include <fstream>
#include <unordered_map>
#include <queue>
#include <stack>
#include <vector>

#define ll long long
#define pb push_back
using namespace std;
ifstream in("dijkstra.in");
ofstream out("dijkstra.out");

const int NMax = 5e4 + 5;
const int inf = 1e9 + 5;

int N,M;
int dist[NMax];

struct elem {
    int y,c;
    elem(int _y = 0,int _c = 0) {
        y = _y;
        c = _c;
    }
};

bool operator <(elem a,elem b) {
    return a.c > b.c;
}
vector<elem> v[NMax];

int main() {
    in>>N>>M;

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

        v[x].pb(elem(y,c));
    }

    for (int i=1;i <= N;++i) {
        dist[i] = inf;
    }

    dist[1] = 0;
    priority_queue<elem> Q;
    Q.push(elem(1,0));
    while (Q.size()) {
        int node = Q.top().y,
            d = Q.top().c;
        Q.pop();

        if (dist[node] < d) {
            continue;
        }

        for (elem el : v[node]) {
            int nxt = el.y, cost = el.c;
            if (dist[nxt] <= dist[node] + cost) {
                continue;
            }

            dist[nxt] = dist[node] + cost;
            Q.push(elem(nxt,dist[nxt]));
        }
    }

    for (int i=2;i <= N;++i) {
        out<<( (dist[i] == inf) ? 0 : dist[i])<<' ';
    }

    in.close();out.close();
    return 0;
}