Compilare: main.cpp: In function 'std::vector<int> matches(std::__cxx11::string, int)': main.cpp:9:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < s.size (); i++) { ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:23:40: 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); ^ main.cpp:24:42: 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); ^