Compilare: main.cpp: In function 'void addTrie(trie*, char*, int)': main.cpp:19:14: warning: NULL used in arithmetic [-Wpointer-arith] if(*s == NULL) ^~~~ main.cpp: In function 'void findTrie(trie*, char*)': main.cpp:29:14: warning: NULL used in arithmetic [-Wpointer-arith] if(*s == NULL) ^~~~ main.cpp: In function 'int main()': main.cpp:53:16: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[n] = NULL; ^~~~ main.cpp:62:16: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[n] = NULL; ^~~~ main.cpp:46:15: warning: unused variable 'k' [-Wunused-variable] int i, j, k, n; ^ main.cpp:44:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sub.in", "r", stdin); ^ main.cpp:45:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sub.out", "w", stdout); ^ main.cpp:48:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &na); ^ main.cpp:51:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", s); ^ main.cpp:57:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &nb); ^ main.cpp:60:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", s); ^