Cod sursa(job #2022895)

Utilizator StefanManolacheManolache Stefan StefanManolache Data 17 septembrie 2017 16:55:32
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include <cstdio>
#include <vector>
#include <set>


FILE *fin = fopen("dijkstra.in", "r");
FILE *fout = fopen("dijkstra.out", "w");

#define maxn 500000
#define maxc 5100000000
#define ll long long
#define maxm 250000



std::vector<std::pair<ll, ll>> v[maxm + 1];
std::multiset<std::pair<ll, ll>> s;
std::vector<std::pair<ll, ll>>::iterator it;
ll dist[maxn + 1];


int main()
{
    int n, m, x, y, c;
    fscanf(fin, "%d%d", &n, &m);
    for (int i = 1; i <= m; i++) {
        fscanf(fin, "%d%d%d", &x, &y, &c);
        v[x].push_back (std::make_pair(y, c));

    }
    for (int i = 2; i <= n; i++)
        dist[i] = maxc;
    dist[1] = 0;
    s.insert(std::make_pair(0, 1));
    while(s.empty() == 0) {
        int p = s.begin()->second;
        s.erase(s.begin());
        for (it = v[p].begin(); it != v[p].end(); it++) {
            y = it->first;
            c = it->second;
            if (dist[y] > dist[p] + c) {
                if (dist[y] != maxc)
                    s.erase(s.find(std::make_pair(dist[y], y)));
                dist[y] = dist[p] + c;
                s.insert(std::make_pair(dist[y], y));
            }
        }
    }

    for (int i = 2; i <= n; i++) {
        if (dist[i] == maxc)
            fprintf(fout, "0");
        else
            fprintf(fout, "%lld", dist[i]);
        fprintf(fout, " ");
    }
    return 0;
}