Compilare: user.cpp: In function ‘std::vector<int> intersectie(std::vector<int>, std::vector<int>)’: user.cpp:14:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();i++) ~^~~~~~~~~ user.cpp: In function ‘std::vector<int> reuniune(std::vector<int>, std::vector<int>)’: user.cpp:31:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();i++) ~^~~~~~~~~ user.cpp:33:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<b.size() && b[j]<a[i]) ~^~~~~~~~~ user.cpp:38:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j>=b.size() or b[j]!=a[i]) ~^~~~~~~~~~ user.cpp:43:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<b.size()) ~^~~~~~~~~ user.cpp: In function ‘std::vector<int> rezolva()’: user.cpp:80:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v4.size();i++) ~^~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:127:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] v.push_back(val[s[i]]); ^