Cod sursa(job #3162296)

Utilizator Raul_AArdelean Raul Raul_A Data 28 octombrie 2023 19:49:14
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define eb emplace_back
#define cin in
#define cout out
using namespace std;

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

const int MAX=50000;
int cost[MAX+5]; 

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

int n,m,x,y,z;
vector<pii> v[MAX+5];///din x -> y cost z
priority_queue<int,vector<int>,cmp> Q;
bitset<MAX+5> inpq;

void dijkstra(int start) 
{
    Q.push(start);
    cost[start]=0;
    inpq[start]=1;
    
    while(!Q.empty())
    {
        int nod=Q.top();
        Q.pop();
        inpq[nod]=0;
        for(auto x: v[nod])
        {
            int next,w;
            tie(next,w)=x;
            if(cost[nod]+w<cost[next])
            {
                cost[next]=cost[nod]+w;
                if(!inpq[next])
                    Q.push(next),inpq[next]=1;
            }
        }
    }
}

int main()
{
    cin>>n>>m;
    
    for(int i=1;i<=m;i++)
    {
        cin>>x>>y>>z;
        v[x].eb(y,z);
    }
    
    for(int i=1;i<=n;i++)
        cost[i]=2e9;
    
    dijkstra(1);
    
    for(int i=2;i<=n;i++,cout<<' ')
        if(cost[i]==2e9)
            cout<<0;
        else
            cout<<cost[i];
    return 0;
}