Compilare: user.cpp: In function ‘int main()’: user.cpp:37:10: warning: unused variable ‘ok’ [-Wunused-variable] bool ok = true; ^ user.cpp:30:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("exp.in","r",stdin); ^ user.cpp:31:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("exp.out","w",stdout); ^ user.cpp:33:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&m); ^ user.cpp:34:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:35:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sir); ^ /tmp/ccdZIwIw.o: In function `main': user.cpp:(.text.startup+0x80): warning: the `gets' function is dangerous and should not be used.