Compilare: user.cpp: In function ‘int main()’: user.cpp:37:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j <= x.size() - 1; ++j) { ^ user.cpp:28:29: warning: unused variable ‘r_1’ [-Wunused-variable] int r_x, r_y, j_x, j_y, r_1, r_2, r_3, min_time = big; ^ user.cpp:28:34: warning: unused variable ‘r_2’ [-Wunused-variable] int r_x, r_y, j_x, j_y, r_1, r_2, r_3, min_time = big; ^ user.cpp:28:39: warning: unused variable ‘r_3’ [-Wunused-variable] int r_x, r_y, j_x, j_y, r_1, r_2, r_3, min_time = big; ^