Compilare: user.cpp: In function ‘int rezolva(int)’: user.cpp:61:14: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] iv[i]=NULL; ^ user.cpp:62:16: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] a[poz][j+1]=NULL; ^ user.cpp:12:32: warning: unused variable ‘inv’ [-Wunused-variable] int lg,i,x,y,nr=0,s=0,cs,j,inv=0; ^ user.cpp: In function ‘int main()’: user.cpp:77:17: warning: NULL used in arithmetic [-Wpointer-arith] if(a[i][0]!=NULL) ^ user.cpp:67:6: warning: unused variable ‘v’ [-Wunused-variable] char v; ^