Compilare: user.cpp: In function ‘int Nextint()’: user.cpp:26:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;i < strlen(S);i++) ^ user.cpp:21:18: 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:56:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copaci.in","r",stdin); ^ user.cpp:57:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copaci.out","w",stdout); ^