Compilare: user.cpp: In function ‘void prim()’: user.cpp:49:13: warning: variable ‘_cost’ set but not used [-Wunused-but-set-variable] int _cost, _nod; ^ user.cpp: In function ‘void citire()’: user.cpp:19:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:25:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &tmp1, &tmp2, &tmp3); ^ user.cpp: In function ‘int main()’: user.cpp:85:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in", "r", stdin); ^ user.cpp:86:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out", "w", stdout); ^