Compilare: user.cpp: In function ‘void print_divs()’: user.cpp:29:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<divs.size();++i) { ^ user.cpp: In function ‘int main()’: user.cpp:51:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < divs.size(); ++i) { ^ user.cpp:36:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perm2.in", "r", stdin); ^ user.cpp:37:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perm2.out", "w", stdout); ^