Cod sursa(job #3285681)

Utilizator Mateixx1Trandafir matei Mateixx1 Data 13 martie 2025 12:44:17
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.71 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
const int NMAX = 50001,
          INF = 1 << 29;

struct muchie {
    int y, w;
    muchie(int yy = 0, int ww = 0): y(yy), w(ww) {}
};
int N, M, D[NMAX];
bool InQ[NMAX];///InQ[i] = 1 <==> nodul i este in coada
class Comp { ///pt coada cu prioritate
public:
    bool operator()(int a, int b) const {
        return D[a]>D[b];
    }
};

vector<muchie> G[NMAX];
priority_queue<int, vector<int>,Comp> Q;
void citire() {
    int x,y,c;
    f>>N>>M;
    for(int i = 1; i <= M; i++) {
        f>>x>>y>>c;
        G[x].push_back(muchie(y, c));
    }
}
void Dijkstra(int nod) {
    int crt, cost;
    D[nod] = 0;
    InQ[nod] = 1;
    Q.push(nod);
    while(!Q.empty()) {
        crt = Q.top();///Se extrage varful aflat la distanta minima fata de "nod"
        Q.pop();
        InQ[crt] = 0;
        ///Se parcurg arcele care poleaca din varful crt si se optimizeaza
        ///consturile drumurilor pentru varfurile care sunt extremitati finale
        ///ale acestor arce
        for(const muchie &mm : G[crt]) {
            cost=D[crt]+mm.w;
            if(D[mm.y]>cost) {
                D[mm.y]=cost;
                if(!InQ[mm.y]) {
                    Q.push(mm.y);
                    InQ[mm.y]=1;
                }
            }
        }
    }
}
int main() {
    int i;
    citire();
    for(i=1; i<=N; i++) {
        D[i]=INF;
    }
    Dijkstra(1);
    for(i=2; i<=N; i++) {
        if(D[i]==INF) {
            g<<"0 ";
        } else {
            g<<D[i]<<' ';
        }
    }
    f.close();
    g.close();
    return 0;
}