Compilare: user.cpp: In function ‘int main()’: user.cpp:15:18: warning: ‘xa’ may be used uninitialized in this function [-Wmaybe-uninitialized] int d1=xa*yb + xb*yd + xd*ya - yb*xd - yd*xa - ya*xb; ^ user.cpp:15:18: warning: ‘yb’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:15:26: warning: ‘xb’ may be used uninitialized in this function [-Wmaybe-uninitialized] int d1=xa*yb + xb*yd + xd*ya - yb*xd - yd*xa - ya*xb; ^ user.cpp:15:26: warning: ‘yd’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:15:34: warning: ‘xd’ may be used uninitialized in this function [-Wmaybe-uninitialized] int d1=xa*yb + xb*yd + xd*ya - yb*xd - yd*xa - ya*xb; ^ user.cpp:15:34: warning: ‘ya’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:16:18: warning: ‘yc’ may be used uninitialized in this function [-Wmaybe-uninitialized] int d2=xb*yc + xc*yd + xd*yb - yc*xd - yd*xb - yb*xc; ^ user.cpp:16:26: warning: ‘xc’ may be used uninitialized in this function [-Wmaybe-uninitialized] int d2=xb*yc + xc*yd + xd*yb - yc*xd - yd*xb - yb*xc; ^