Compilare: user.cpp: In function ‘int main()’: user.cpp:41:9: warning: unused variable ‘j’ [-Wunused-variable] int i, j, a, b, c; ^ user.cpp:42:8: warning: unused variable ‘del’ [-Wunused-variable] edge* del; ^ user.cpp:43:31: 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:44:33: 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); ^ user.cpp:45:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:47:83: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i = 1; i <= m; i++) scanf("%d%d%d", &a, &b, &c), pq.push(*new edge(a, b, c)); ^