A number $x\in\mathbb{R}$ is said to be algebraic if it is the root of a polynomial over $\mathbb{Q}$. Define $A:[0,1]\rightarrow \{0,1\}$ as $$A(x)=1 \text { if } x \text{ is algebraic, } A(x)=0\text{ if } x \text{ is not algebraic, }$$
What is the value of $\int_{0}^{1} A(x)dx$ ?