Compilare: user.cpp: In function ‘void trie_push()’: user.cpp:10:13: warning: unused variable ‘kk’ [-Wunused-variable] int u=1,kk=0; ^ user.cpp: In function ‘int main()’: user.cpp:50:32: 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:51:34: 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: In function ‘void trie_push()’: user.cpp:24:24: warning: ‘id’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(!child[u][id]) child[u][id]=++triesize; ^