Cod sursa(job #1940009)

Utilizator MaligMamaliga cu smantana Malig Data 26 martie 2017 12:14:54
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

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

const int NMax = 5e4 + 5;
typedef long long ll;
const int inf = 1e9;

int N,M;
int dist[NMax];

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

vector<elem> v[NMax];
priority_queue<elem> Q;

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

        elem e1(y,c),e2(x,c);
        v[x].push_back(e1);
    }

    for (int i=2;i<=N;++i) {
        dist[i] = inf;
    }
    dist[1] = 0;
    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;
        }

        for (int k=0;k < (int)v[nod].size();++k) {
            int son = v[nod][k].y, cost = v[nod][k].c;
            if (dist[son] > dist[nod] + cost) {
                dist[son] = dist[nod] + cost;

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

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

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