Cod sursa(job #2875974)

Utilizator fastlikearabbitDaniel Ghenghea fastlikearabbit Data 22 martie 2022 19:16:47
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.88 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
#include<limits.h>

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

const int NMAX = 50005;
int N, M, startNode = 1;
int oo = INT_MAX;

vector<pair<int, int>> adj[NMAX];
int distances[NMAX];
bool visited[NMAX];

struct comp {
    bool operator() (int x, int y) {
        return distances[x] > distances[y];
    }
};
priority_queue<int, vector<int>, comp> q;

void read() {
    fin >> N >> M;
    
    for(int i = 1; i <= M; i++) {
        int from, to, weight;
        
        fin >> from >> to >> weight;
        adj[from].push_back(make_pair(to, weight));
    }
    
    for(int i = 2; i <= N; i++)
        distances[i] = oo;
    distances[startNode] = 0;
    
    for(int i = 2; i <= N; i++)
        visited[i] = false;
}

void solve() {
    q.push(startNode);
    visited[startNode] = true;
    
    while(!q.empty()) {
        int currentNode = q.top();
        q.pop();
      //  visited[currentNode] = false;
        //int node = currentNode.first;
        //int weight = currentNode.second;
      
        
        for(int i = 0; i  < adj[currentNode].size(); i++) {
            int neighbour = adj[currentNode][i].first;
            int weight = adj[currentNode][i].second;
            
            if(distances[currentNode] + weight < distances[neighbour]) {
                distances[neighbour] = distances[currentNode] + weight;
                
                if(!visited[neighbour]) {
                    visited[neighbour] = true;
                    q.push(neighbour);
                }
            }
        }
        
    }
    }


void write() {
    for(int i = 2; i <= N; i++) {
        if (distances[i] == oo)
            fout << "0 ";
        else
            fout << distances[i] << " ";
    }
}

int main() {
    read();
    solve();
    write();
    
    //cout << oo;
    
    return 0;
}