Compilare: user.cpp: In function ‘int main()’: user.cpp:43:9: warning: unused variable ‘a’ [-Wunused-variable] int a,b,c; ^ user.cpp:43:11: warning: unused variable ‘b’ [-Wunused-variable] int a,b,c; ^ user.cpp:43:13: warning: unused variable ‘c’ [-Wunused-variable] int a,b,c; ^ user.cpp:41:28: 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:47:52: 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].a,&v[i].b,&v[i].c); ^