Compilare: user.cpp: In function ‘int main()’: user.cpp:54:11: warning: unused variable ‘a’ [-Wunused-variable] int x,y,a,b; ^ user.cpp:55:34: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] fout <<read(y,b) - read(x-1,y-1)+1; ^ user.cpp:55:34: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:32:38: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] y1 -= y1 & -y1; ^ user.cpp:54:13: note: ‘b’ was declared here int x,y,a,b; ^