Compilare: user.cpp: In function ‘void read()’: user.cpp:57:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sarpe.in", "r", stdin); ^ user.cpp:58:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); v[0] = strlen(s); ^ user.cpp:61:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sarpe.out", "w", stdout); ^ user.cpp: In function ‘void write()’: user.cpp:81:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sarpe.out", "w", stdout); ^ /tmp/ccJwaioF.o: In function `read()': user.cpp:(.text+0x250): warning: the `gets' function is dangerous and should not be used.