Cod sursa(job #3149004)

Utilizator BlaugranasEnal Gemaledin Blaugranas Data 5 septembrie 2023 17:51:52
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.09 kb
#include<fstream>
#include<vector>
using namespace std;
ifstream F("dijkstra.in");
ofstream G("dijkstra.out");
#define N 50001
vector<pair<int,int> > g[N];
int m,n,i,j,k,p[N],d[N],h[N],l,t,w,f;
int main()
{
    F>>n>>m;
    while(m--)
        F>>i>>j>>k,g[i].push_back({j,k});
    for(i=2;i<=n;++i)
        d[i]=p[i]=N;
    for(k=0,p[1]=h[++k]=1;k;) {
        for(t=h[1],h[1]=h[k--],p[h[1]]=w=1;(w<<1)<=k;w=f) {
            f=w<<1;
            if(f<k&&d[h[f+1]]<d[h[f]])
                f++;
            if(d[h[w]]<=d[h[f]])
                break;
            swap(h[w],h[f]),p[h[w]]=w,p[h[f]]=f;
        }
        for(i=0,l=g[t].size();i<l;++i) {
            if(d[g[t][i].first]>d[t]+g[t][i].second) {
                d[g[t][i].first]=d[t]+g[t][i].second;
                if(p[g[t][i].first]==N)
                    h[++k]=g[t][i].first,p[h[k]]=k;
                for(w=p[g[t][i].first];w>1&&d[h[w>>1]]>d[h[w]];w=f)
                    f=w>>1,swap(h[w],h[f]),p[h[w]]=w,p[h[f]]=f;
            }
        }
    }
    for(i=2;i<=n;++i)
        G<<(d[i]==N?0:d[i])<<" ";
    return 0;
}