Compilare: user.cpp: In function ‘int main()’: user.cpp:132:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2;i < strlen(V);i++) ^ user.cpp:142:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < strlen(V);i++) ^ user.cpp:121:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apel.in","r",stdin); ^ user.cpp:122:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apel.out","w",stdout); ^ user.cpp:124:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",S); ^