Cod sursa(job #3241971)

Utilizator Edyci123Bicu Codrut Eduard Edyci123 Data 6 septembrie 2024 18:18:18
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include <bits/stdc++.h>

#define DIM 50005
#define INF 0x3f3f3f3f

#define first index
#define second cost

using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

struct TNode {
    int index;
    int cost;

    bool operator <(const TNode node) const {
        return this->cost <= node.cost;
    }
};

int n, m;
int dist[DIM];
vector<TNode> edges[DIM];
set<TNode> s;

void dijkstra(int startingPoint) {
    dist[startingPoint] = 0;
    s.insert({startingPoint, dist[startingPoint]});

    while (!s.empty()) {
        int index = s.begin()->index;
        s.erase(s.begin());

        for (TNode edge: edges[index]) {
            if (dist[edge.index] > dist[index] + edge.cost) {
                if (dist[edge.index] != INF) {
                    s.erase({edge.index, dist[edge.index]});
                }
                dist[edge.index] = dist[index] + edge.cost;
                s.insert({edge.index, dist[edge.index]});
            }
        }
    }
}

int main() {

    f >> n >> m;
    
    for (int i = 0; i < m; i++) {
        int x, y, cost;
        f >> x >> y >> cost;
        edges[x].push_back({y, cost});
    }

    for (int i = 1; i <= n; i++) {
        dist[i] = INF;
    }

    dijkstra(1);

    for (int i = 2; i <= n; i++) {
        if (dist[i] == INF) {
            g << "0 ";
        } else { 
            g << dist[i] << " ";
        }
    }

    return 0;
}