Compilare: user.cpp: In function ‘void insertTrie(Trie*, char*)’: user.cpp:56:15: warning: NULL used in arithmetic [-Wpointer-arith] if (*s == NULL) { ^ user.cpp: In function ‘int ord(char)’: user.cpp:19:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘char ch(int)’: user.cpp:27:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:107:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("rps.in", "r", stdin); ^ user.cpp:108:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("rps.out", "w", stdout); ^ user.cpp:110:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d%d ", &N, &K, &W, &D); ^ user.cpp:113:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets (s); ^ /tmp/ccrqWH3M.o: In function `main': user.cpp:(.text.startup+0x88): warning: the `gets' function is dangerous and should not be used.