Compilare: user.cpp: In function ‘void get_edges()’: user.cpp:17:9: warning: unused variable ‘nn’ [-Wunused-variable] int nn = 0; ^ user.cpp: In function ‘int main()’: user.cpp:76:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("towers.in", "r", stdin); ^ user.cpp:77:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("towers.out", "w", stdout); ^ user.cpp:79:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &k); ^ user.cpp:82:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &a[i].val), a[i].ind = i; ^ user.cpp:89:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &H[i].val), H[i].ind = i; ^