Compilare: user.cpp: In function ‘void place1(int, int, int&)’: user.cpp:18:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,k,o; ^ user.cpp:18:13: warning: variable ‘k’ set but not used [-Wunused-but-set-variable] int i,j,k,o; ^ user.cpp:18:15: warning: unused variable ‘o’ [-Wunused-variable] int i,j,k,o; ^