Compilare: user.cpp: In function ‘int main()’: user.cpp:89:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<answer.size();i++) ^ user.cpp:42:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("centru2.in","r",stdin); ^ user.cpp:43:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("centru2.out","w",stdout); ^ user.cpp:46:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:49:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].left,&v[i].right); ^