Compilare: user.cpp: In function ‘void write()’: user.cpp:94:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<circuit.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:102:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ciclueuler.in","r",stdin); ^ user.cpp:103:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ciclueuler.out","w",stdout); ^ user.cpp:104:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:107:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^