Compilare: user.cpp: In function ‘int main()’: user.cpp:27:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < D.size(); j++) { ^ user.cpp:13:24: warning: unused variable ‘left’ [-Wunused-variable] int n, i, ans = 1, left, st, dr, sum, x; ^ user.cpp:13:30: warning: unused variable ‘st’ [-Wunused-variable] int n, i, ans = 1, left, st, dr, sum, x; ^ user.cpp:13:34: warning: unused variable ‘dr’ [-Wunused-variable] int n, i, ans = 1, left, st, dr, sum, x; ^