Compilare: user.cpp: In function ‘void adauga_elimina(char*, int)’: user.cpp:18:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(s);i++) ^ user.cpp: In function ‘int nraparitii(char*)’: user.cpp:36:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(s) && v[nod].urm[s[i]-'a'];i++) nod=v[nod].urm[s[i]-'a']; ^ user.cpp:37:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<strlen(s)) return 0; ^ user.cpp: In function ‘int prefix(char*)’: user.cpp:44:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(s);i++) ^ user.cpp:51:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==strlen(s)) sol=i; ^ user.cpp: In function ‘int main()’: user.cpp:58:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trie.in", "r", stdin); ^ user.cpp:59:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trie.out", "w", stdout); ^ user.cpp:63:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %s\n",&x,s); ^