Compilare: user.cpp: In function ‘int main()’: user.cpp:53:29: warning: format ‘%d’ expects argument of type ‘int*’, but argument 2 has type ‘long long unsigned int*’ [-Wformat=] scanf("%d", vals + i); ^ user.cpp:48:9: warning: unused variable ‘val’ [-Wunused-variable] int val; ^ user.cpp:46:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("huffman.in", "r", stdin); ^ user.cpp:47:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("huffman.out", "w", stdout); ^ user.cpp:50:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:53:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", vals + i); ^