Compilare: user.cpp: In function ‘int main()’: user.cpp:11:15: warning: unused variable ‘i’ [-Wunused-variable] int b, p, i, j, l, fb; ^ user.cpp:9:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("subbit.in", "r", stdin); ^ user.cpp:10:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("subbit.out", "w", stdout); ^ user.cpp:13:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ /tmp/ccxHOR7m.o: In function `main': user.cpp:(.text.startup+0x5a): warning: the `gets' function is dangerous and should not be used.