Compilare: user.cpp: In function ‘long int equal_pos(char*)’: user.cpp:16:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(expresie);i++) ^ user.cpp: In function ‘void rezolvare_stang(char*)’: user.cpp:78:24: warning: NULL used in arithmetic [-Wpointer-arith] while(ecuatie[i]!=NULL) ^ user.cpp:138:23: warning: NULL used in arithmetic [-Wpointer-arith] while(ecuatie[i]!=NULL) ^ user.cpp: In function ‘long int equal_pos(char*)’: user.cpp:19:1: warning: control reaches end of non-void function [-Wreturn-type] } ^