Compilare: main.cpp: In function 'trie* Insert(trie*, char*)': main.cpp:33:12: warning: NULL used in arithmetic [-Wpointer-arith] if(*s==NULL) ^~~~ main.cpp: In function 'int main()': main.cpp:56:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("kc.in","r",stdin); ^ main.cpp:57:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("kc.out","w",stdout); ^ main.cpp:59:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ main.cpp:61:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("\n"); ^ main.cpp:63:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s",str); ^ main.cpp:67:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("\n"); ^ main.cpp:68:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s",s); ^