Compilare: user.cpp: In function ‘int main()’: user.cpp:17:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<pattern.size();++i) ^ user.cpp:26:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i<text.size()) ^ user.cpp:30:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j==pattern.size()-1) ^ user.cpp:10:35: 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:11:37: 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); ^