Compilare: user.cpp: In function ‘void readFile()’: user.cpp:30:12: warning: unused variable ‘a’ [-Wunused-variable] int i, a, b; ^ user.cpp:30:15: warning: unused variable ‘b’ [-Wunused-variable] int i, a, b; ^ user.cpp:28:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d%d%d", &n, &mx, &l); ^ user.cpp:33:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d%d", &v[i].d, &v[i].c); ^