Compilare: user.cpp: In function ‘int main()’: user.cpp:23:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[a].size();i++){ ~^~~~~~~~~~~~ user.cpp:35:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v[nod].size();j++){ ~^~~~~~~~~~~~~~ user.cpp:15:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&n,&m); ^ user.cpp:17:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d%d",&a,&b,&cost); ^