Compilare: main.cpp: In function 'bool isSubSequence(std::__cxx11::string, std::__cxx11::string)': main.cpp:5:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < b.size() && j < a.size(); ++i) { ~~^~~~~~~~~~ main.cpp:5:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < b.size() && j < a.size(); ++i) { ~~^~~~~~~~~~ main.cpp:11:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return j == a.size(); ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:16:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("search.out", "w", stdout); ^