Compilare: user.cpp: In function ‘void adaug(nod*, char*, int)’: user.cpp:19: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int del(nod*, char*, int)’: user.cpp:31: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int query(nod*, char*, int)’: user.cpp:45: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int prefix(nod*, char*, int)’: user.cpp:52: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:63: warning: format ‘%s’ expects type ‘char*’, but argument 3 has type ‘char (*)[21]’ user.cpp:59: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:60: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result