Compilare: user.cpp: In function ‘std::vector<int> karatsuba(std::vector<int>&, std::vector<int>&)’: user.cpp:24:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v1.size()/2; ++i) ^ user.cpp:26:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (size > v1.size()/2) ^ user.cpp:28:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=v1.size()/2; i<v1.size(); ++i) ^ user.cpp:31:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v2.size()/2; ++i) ^ user.cpp:33:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (size > v1.size()/2) ^ user.cpp:35:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=v2.size()/2; i<v2.size(); ++i) ^ user.cpp:42:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<x0.size(); ++i) ^ user.cpp:44:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<y0.size(); ++i) ^ user.cpp:49:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<z1.size(); ++i) ^ user.cpp:55:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<z1.size(); ++i) ^ user.cpp:57:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<z2.size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:77:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (x >= v1.size()) ^ user.cpp:87:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (x >= v2.size()) ^ user.cpp:96:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=v2.size(); i <v1.size(); ++i) ^ user.cpp:101:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v.size(); ++i) ^