Compilare: user.cpp: In function ‘int main()’: user.cpp:36:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<la; i++) ~^~~ user.cpp:46:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<la; i++) ~^~~ user.cpp:53:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=la; i<lb; i++) ~^~~ user.cpp:43:9: warning: unused variable ‘c’ [-Wunused-variable] llu c=0; ^