Cod sursa(job #2871126)

Utilizator mateisebastian4Matei Sebastian mateisebastian4 Data 12 martie 2022 21:30:53
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.32 kb
#include <iostream>
#include <queue>
#include <fstream>
#include <bitset>
#include <vector>
using namespace std;
const int N=2134151,nr=1424155;
int dp[N],n,m;
ifstream fin ("dijkstra.in");
ofstream fout("dijkstra.out");

struct pereche{
int y,cost;
};

struct comparare {
bool operator()(pereche A,pereche B){
return dp[A.y]>dp[B.y];
}
};

vector <pereche>v[N];
bitset <N>inq;
priority_queue<pereche,vector<pereche>,comparare>q;

void cit(){
pereche w;
fin>>n>>m;
int x,y,cost;
while(fin>>x>>y>>cost)
{
    w.y=y;
    w.cost=cost;
    v[x].push_back(w);
}

}
void init(int n)
{
    for(int i=1;i<=n;i++)
        dp[i]=nr;
}
void bfs()
{
    pereche x;
    inq[1]=true;
    x.y=1;
    x.cost=0;
    dp[1]=0;
    q.push(x);
    while(!q.empty())
    {
      x=q.top();
      q.pop();
      inq[x.y]=false;
      for(auto y:v[x.y])
      {
          if(dp[y.y]>dp[x.y]+y.cost)
          {
              dp[y.y]=dp[x.y]+y.cost;
              if(!inq[y.y])
              {
                  inq[y.y]=true;
                  q.push(y);
                }
            }
        }
    }
}

int main()
{
    cit();
    init(n+1);
    bfs();
    for(int i=2;i<=n;i++)
        if(dp[i]==nr)
        {
        fout<<0<<" ";
        continue;
        }
    else fout<<dp[i]<<" ";

}