Compilare: main.cpp: In function 'void big_add(std::deque<int>&, std::deque<int>&)': main.cpp:33:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();i++) ~^~~~~~~~~ main.cpp:35:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i>=a.size()) ~^~~~~~~~~~ main.cpp: In function 'void big_mul(std::deque<int>&, int)': main.cpp:59:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a.size();i++,t/=10) ~^~~~~~~~~ main.cpp: In function 'ull factorial(int)': main.cpp:124:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(ull i=1;i<=n;i++) ~^~~ main.cpp: In function 'int main()': main.cpp:153:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<frecv.size();i++) ~^~~~~~~~~~~~~