Cod sursa(job #2933890)

Utilizator LucaT2Tasadan Luca LucaT2 Data 5 noiembrie 2022 13:34:22
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.87 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
vector <pair<int,int>> lista[100005];
int viz[100005];
priority_queue<pair<int,int>>Q;
void citire(int &n,int &m){
    int x,y,cost;
    fin>>n>>m;
    for(int i=1;i<=m;i++){
        fin>>x>>y>>cost;
        lista[x].push_back({y,cost});

    }
}
int dp[100005];
void bellman_ford(int p){
    int n,m;
    citire(n,m);
    queue <int> q;
    for(int i=1;i<=n;i++)
        dp[i]=-1;
    dp[p]=0;
    q.push(p);
    viz[p]=1;
    while(!q.empty()){
        int x=q.front();
        q.pop();
        viz[x]=0;
        for(auto vecin:lista[x]){
            int cost;
            cost=dp[x]+vecin.second;
            if(dp[vecin.first]==-1 || dp[vecin.first]>cost){
                dp[vecin.first]=cost;
                if(!viz[vecin.first])
                q.push(vecin.first);
                viz[vecin.first]=1;
            }
        }
    }
    for(int i=2;i<=n;i++){
        if(dp[i]!=-1){
        fout<<dp[i]<<" ";
        }
        else
            fout<<0<<" ";
    }
}

void dijkstra(int p){
    int n,m;
    citire(n,m);
    queue <int> q;
    for(int i=1;i<=n;i++)
        dp[i]=INT_MAX;
    dp[p]=0;
    Q.push({0,p});
    while(!Q.empty()){
        int x= Q.top().second;
        Q.pop();
        if(viz[x]) continue;
        viz[x]=1;
        for(auto vecin:lista[x]){
            int cost;
            cost=dp[x]+vecin.second;
            if(dp[vecin.first]>cost){
                dp[vecin.first]=cost;
                if(!viz[vecin.first]){
                    Q.push({-dp[vecin.first],vecin.first});
                }
            }
        }
    }
    for(int i=2;i<=n;i++)
        if(dp[i]==INT_MAX)
        fout<<0<<" ";
    else
        fout<<dp[i]<<" ";
}
int main()
{
    dijkstra(1);
    return 0;
}