Cod sursa(job #2575181)

Utilizator SebaschanSebastian Cojocaru Sebaschan Data 6 martie 2020 11:59:54
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.45 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;

ifstream r("dijkstra.in");
ofstream w("dijkstra.out");

const int NMAX = 50001;
const int oo = (1 << 30);

int N, M, D[NMAX];
bool inQ[NMAX];

vector <pair <int, int> > G[NMAX];

struct comp {
    bool operator()(int x, int y) {
        return D[x] > D[y];
    }
};

priority_queue < int, vector < int >, comp> q;

void Read() {
    r>>N>>M;
    int x, y, c;
    for(int i = 1; i <= M; i++) {
        r>>x>>y>>c;
        G[x].push_back(make_pair(y, c));
    }
}

void Dijkstra(int nodStart) {
    for(int i = 1; i <= N; i++)
        D[i] = oo;
    D[nodStart] = 0;
    q.push(nodStart);
    inQ[nodStart] = true;
    while(!q.empty()) {
        int nodCur = q.top();
        q.pop();
        inQ[nodCur] = false;
        for(size_t i = 0; i < G[nodCur].size(); i++) {
            int nnod = G[nodCur][i].first; //nod vecin
            int cost = G[nodCur][i].second;
            if(D[nodCur] + cost < D[nnod]) {
                D[nnod] = D[nodCur] + cost;
                if(inQ[nnod] == false) {
                    q.push(nnod);
                    inQ[nnod] = true;
                }
            }
        }
    }
}

void Show() {
    for(int i = 2; i <= N; i++) {
        if(D[i] != oo)
            w<<D[i]<<" ";
        else w<<"0 ";
    }
}

int main() {
    Read();
    Dijkstra(1);
    Show();
    return 0;
}