Compilare: user.cpp: In function ‘char bun()’: user.cpp:117:10: warning: unused variable ‘a1’ [-Wunused-variable] double a1, a2, a3, u1, u2, u3; ^ user.cpp:117:14: warning: unused variable ‘a2’ [-Wunused-variable] double a1, a2, a3, u1, u2, u3; ^ user.cpp:117:18: warning: unused variable ‘a3’ [-Wunused-variable] double a1, a2, a3, u1, u2, u3; ^ user.cpp: In function ‘char readch()’: user.cpp:27:26: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(s, 1, BUFF, in); ^