Compilare: user.cpp: In function ‘void test()’: user.cpp:31:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < strs[i].size(); ++ j) { ~~^~~~~~~~~~~~~~~~ user.cpp:57:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int st = 0; st < labels.size(); ++ st) ~~~^~~~~~~~~~~~~~~ user.cpp:63:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < labels.size(); ++ i) ~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:69:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adn2.in", "r", stdin); ^ user.cpp:70:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("adn2.out", "w", stdout); ^