Compilare: user.cpp: In function ‘int main()’: user.cpp:50:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i].size();++j) ^ user.cpp:63:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i].size();++j) ^ user.cpp:35:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc3.in","r",stdin); ^ user.cpp:36:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc3.out","w",stdout); ^ user.cpp:38:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:40:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;++i) scanf("%d%d%d",&a[i].x,&a[i].y,&a[i].r); ^