Compilare: user.cpp: In function ‘int main()’: user.cpp:77:9: warning: unused variable ‘n1’ [-Wunused-variable] int i,n1,n2,cost; ^ user.cpp:77:12: warning: unused variable ‘n2’ [-Wunused-variable] int i,n1,n2,cost; ^ user.cpp:77:15: warning: unused variable ‘cost’ [-Wunused-variable] int i,n1,n2,cost; ^ user.cpp:78:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&n,&m); ^ user.cpp:80:53: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d%d",&v[i].n1,&v[i].n2,&v[i].cost); ^