Compilare: user.cpp:2:125: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] using namespace std;int a[250001][4],d[50001],n,k,s=1,i,j,c,m,l=1;ifstream f("dijkstra.in");ofstream g("dijkstra.out");main(){f>>n>>m;for(i=1;i<=n;i++)d[i]=2000000;d[1]=0;for(i=1;i<=m;i++){f>>a[i][1]>>a[i][2]>>a[i][3];if(a[i][1]==1)d[a[i][2]]=a[i][3];}while(s&&l<n){s=0;for(k=1;k<=m;k++){i=a[k][1];j=a[k][2];c=a[k][3];if(d[j]>d[i]+c){d[j]=d[i]+c;s=1;}}l++;}for(i=2;i<=n;i++)if(d[i]<2000000)g<<d[i]<<' ';else g<<0<<' ';} ^