Compilare: user.cpp: In function ‘int main()’: user.cpp:23:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<V.size();++j){ ^ user.cpp: In function ‘void openIOFiles()’: user.cpp:7:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bleach.in","r",stdin); ^ user.cpp:8:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bleach.out","w",stdout); ^