Compilare: user.cpp: In function ‘int Nextint()’: user.cpp:21:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;i < strlen(S);i++) ^ user.cpp:16:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",S); ^ user.cpp: In function ‘int main()’: user.cpp:43:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("1-sir.in","r",stdin); ^ user.cpp:44:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("1-sir.out","w",stdout); ^