Compilare: user.cpp: In function ‘long long int prod(long long int, long long int, long long int)’: user.cpp:27:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<A.size();i++){ ^ user.cpp:29:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<B.size()||t>0;j++){ ^ user.cpp:30:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j<B.size()) ^ user.cpp: In function ‘int main()’: user.cpp:55:43: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%lld %lld %lld " ,&a,&b,&c); ^