Cod sursa(job #1927886)

Utilizator MaligMamaliga cu smantana Malig Data 15 martie 2017 17:37:49
Problema Algoritmul lui Dijkstra Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 kb
#include <iostream>
#include <fstream>
#include <climits>
#include <vector>
#include <queue>

using namespace std;
ifstream in("dijkstra.in");
ofstream out("dijkstra.out");

const int NMax = 5e5 + 5;
const int inf = INT_MAX;

int N,M;
int dist[NMax];

struct elem {
    int y,c;
    elem() {
        elem(0,0);
    }
    elem(int a,int b) {
        y = a;
        c = b;
    }
};
vector<elem> v[NMax];

bool operator <(elem a,elem b) {
    return a.c>b.c;
}

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

        elem e1(y,c);
        v[x].push_back(e1);
    }

    for (int i=1;i<=N;++i) {
        dist[i] = inf;
    }
    dist[1] = 0;

    priority_queue<elem> Q;
    elem st(1,0);
    Q.push(st);
    while (Q.size()) {
        elem e = Q.top();
        Q.pop();
        int nod = e.y;
        if (dist[nod] < e.c) {
            continue;
        }

        vector<elem>::iterator it;
        for (it = v[nod].begin();it < v[nod].end();++it) {
            int next = it->y, cost = it->c;
            if (dist[next] > dist[nod] + cost) {
                dist[next] = dist[nod] + cost;

                elem n(next,dist[next]);
                Q.push(n);
            }
        }
    }

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

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