Compilare: user.cpp: In function ‘int main()’: user.cpp:40:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= a.size(); i ++) { ^ user.cpp:50:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= b.size() - a.size(); i ++) { ^ user.cpp:60:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= b.size(); i ++) { ^