Compilare: user.cpp: In function ‘int main()’: user.cpp:31:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(a=b+1) ^ user.cpp:22:13: warning: unused variable ‘r’ [-Wunused-variable] int r; ^ user.cpp:14:19: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] int x,y,a,b; ^ user.cpp:14:17: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized] int x,y,a,b; ^