Question

class BPP
{
    unsigned            n;                  /* nº de instancias */
    vector<string>      nombre_instancia;   /* nombre de la instancia*/

In the constructor, I get a segmentation fault (core dumped) when:

file1.open(fich1);
    if (file1.is_open()){
        file1 >> (unsigned &) n;
        for (unsigned k = 0 ; k < n ; ++k){
            getline(file1, nombre_instancia[k]); #gives the segmentation fault

The 2 first lines in fich1 are:

10
 P_0

Answer 1

I guess that you have not resized nombre_instancia beyond its original size of 0. Try this instead:

  file1 >>  n;
  nombre_instancia.resize(n);     
    for (unsigned k = 0 ; k < n ; ++k){
        getline(file1, nombre_instancia[k]); #gives the segmentation fault