Compilare: main.cpp: In function 'int main()': main.cpp:40:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 40 | for(z=0;z<vec[j].size();z++) | ~^~~~~~~~~~~~~~ main.cpp:12:23: warning: unused variable 'l' [-Wunused-variable] 12 | long long n,i,j,k,l,a,b,z; | ^ main.cpp:12:25: warning: unused variable 'a' [-Wunused-variable] 12 | long long n,i,j,k,l,a,b,z; | ^ main.cpp:12:27: warning: unused variable 'b' [-Wunused-variable] 12 | long long n,i,j,k,l,a,b,z; | ^