Compilare: user.cpp: In function ‘void calc(int, long int)’: user.cpp:22:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sk.size()&&!gasit;i++) ^ user.cpp:30:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[p].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:65:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<sk.size()&&!gasit;j++) ^ user.cpp:38:9: warning: unused variable ‘k’ [-Wunused-variable] int k,x,y,op,p; ^