定义在 RRR 上的函数 f(x)f\left( x\right)f(x) 满足 f(x+6)=f(x)f\left( {x + 6}\right) = f\left( x\right)f(x+6)=f(x) ,当 −3≤x<−1- 3 \leq x < - 1−3≤x<−1 时, f(x)=−(x+2)2f\left( x\right) = - {\left( x + 2\right) }^{2}f(x)=−(x+2)2 ,当 −1≤x<3- 1 \leq x < 3−1≤x<3 时, f(x)=xf\left( x\right) = xf(x)=x ,则 f(1)+f(2)+f(3)+⋯f(2012)=f\left( 1\right) + f\left( 2\right) + f\left( 3\right) + \cdots f\left( {2012}\right) =f(1)+f(2)+f(3)+⋯f(2012)=A. 335 B. 338 C. 1678 D. 2012