Compilare: main.cpp: In function 'int main()': main.cpp:104:22: warning: NULL used in arithmetic [-Wpointer-arith] while(s[j]!=NULL) ^~~~ main.cpp:114:23: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[lg]=')',s[lg+1]=NULL; ^~~~ main.cpp:131:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<raspuns.size();i++) ~^~~~~~~~~~~~~~~