Compilare: main.cpp: In function 'Big operator+(const Big&, const Big&)': main.cpp:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<lhs.v.size() || i<rhs.v.size(); ++i) { ~^~~~~~~~~~~~~ main.cpp:15:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<lhs.v.size() || i<rhs.v.size(); ++i) { ~^~~~~~~~~~~~~ main.cpp:17:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i>=ret.v.size()) ret.v.emplace_back(0); ~^~~~~~~~~~~~~~ main.cpp: In function 'Big operator*(const Big&, int)': main.cpp:31:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; i<lhs.v.size(); ++i) { ~^~~~~~~~~~~~~ main.cpp:32:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i>=ret.v.size()) ret.v.emplace_back(0); ~^~~~~~~~~~~~~~ main.cpp:38:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i>=ret.v.size()) ret.v.emplace_back(0); ~^~~~~~~~~~~~~~