Compilare: main.cpp: In function 'std::vector<int> prefix(const string&)': main.cpp:28:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=2;i<=A.size();i++){ ~^~~~~~~~~~ main.cpp: In function 'std::vector<int> KMP(const string&, const string&)': main.cpp:39:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1;i<=A.size();i++){ ~^~~~~~~~~~ main.cpp:42:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (k == B.size()){ ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:54:35: 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); ^ main.cpp:55:37: 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); ^