Compilare: user.cpp: In function ‘std::pair<int, int> ChainEndNodes(int)’: user.cpp:110:9: warning: variable ‘last_k’ set but not used [-Wunused-but-set-variable] int last_k = x, last_nd = x, last_2 = x; ^ user.cpp: In function ‘std::pair<int, int> DistanceDNodes(int, int)’: user.cpp:230:9: warning: variable ‘last_k’ set but not used [-Wunused-but-set-variable] int last_k = x, last_nd = x, last_2 = x; ^ user.cpp: In function ‘int main()’: user.cpp:383:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, op, x, y, D; ^ user.cpp:383:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, op, x, y, D; ^ user.cpp:380:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:386:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &op); ^ user.cpp:388:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp:398:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp:411:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &D); ^ user.cpp:425:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^