Cod sursa(job #1737144)

Utilizator flaviu_2001Craciun Ioan-Flaviu flaviu_2001 Data 3 august 2016 14:08:26
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.47 kb
#include <fstream>
#include <vector>
#include <queue>
#define MAX 50005
#define INF 1<<30

using namespace std;

struct data{
    int edge, weight;
} nd;

vector<data> v[MAX];

int nodes, edges, distances[MAX];
int initial_point(1), vs;
bool visited[MAX];

void scan();
void solve();
int minQ();
void write();

int main(){
    scan();
    solve();
    write();
    return 0;
}

void scan(){
    ifstream fin ("dijkstra.in");
    fin >> nodes >> edges;
    int x, y, z, m = edges;
    while(m--){
        fin >> x >> y >> z;
        nd.edge = y, nd.weight = z;
        v[x].push_back(nd);
    }
    for (int i = 1; i <= nodes; ++i)
        distances[i] = INF;
    fin.close();
}

void solve(){
    distances[initial_point] = 0;

    while(vs != nodes){
        int k = minQ();
        for (unsigned int i = 0; i < v[k].size(); ++i)
            if (distances[v[k][i].edge] > distances[k] + v[k][i].weight)
                distances[v[k][i].edge] = distances[k] + v[k][i].weight;
    }
}

int minQ(){
    int mn = INF, k;
    for (int i = 1; i < nodes; ++i)
        if (distances[i] < mn && !visited[i])
            mn = distances[i],
            k = i;
    visited[k] = 1;
    ++vs;
    return k;
}

void write(){
    ofstream fout ("dijkstra.out");
    for (int i = 1; i <= nodes; ++i)
        if (i == initial_point)
            continue;
        else fout << (distances[i] == INF ? 0 : distances[i]) << " ";
    fout.close();
}