Compilare: user.cpp: In function ‘int main()’: user.cpp:18:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<S1.size();++i) ^ user.cpp:24:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=A+1;i<=S1.size()-1;++i) ^ user.cpp:11:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in","r",stdin); ^ user.cpp:12:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out","w",stdout); ^