Compilare: user.cpp: In function ‘long long int rezolva(int)’: user.cpp:63:14: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] iv[i]=NULL; ^ user.cpp:64:16: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] a[poz][j+1]=NULL; ^ user.cpp:12:20: warning: unused variable ‘inv’ [-Wunused-variable] int lg,i,x,y,j,inv=0; ^ user.cpp: In function ‘int main()’: user.cpp:79:17: warning: NULL used in arithmetic [-Wpointer-arith] if(a[i][0]!=NULL) ^ user.cpp:69:6: warning: unused variable ‘v’ [-Wunused-variable] char v; ^