Compilare: user.cpp: In function ‘int main()’: user.cpp:75:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < b.size(); ++i) ^ user.cpp:79:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); ++i) ^ user.cpp:85:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a.size(); ++i) ^ user.cpp:90:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); ++i) ^ user.cpp:96:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a.size(); ++i) ^ user.cpp:99:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < b.size(); ++i) ^ user.cpp:102:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); ++i) ^