Compilare: user.cpp: In function ‘bool check(int, int)’: user.cpp:58:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(V.back() == U.size() - 1) ^ user.cpp:62:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(t = V.back() + 1; t < U.size(); t++) { ^ user.cpp: In function ‘int main()’: user.cpp:101:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inputFile.c_str(), "r", stdin); ^ user.cpp:102:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outputFile.c_str(), "w", stdout); ^ user.cpp:105:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ user.cpp:108:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", S + 1); ^