$x$	$-1$	$0$	$1$	$2$	$3$	$4$
$f\left(x\right)$	1	1	1	1	2	3

$f\left(-1\right)=1$  

$f\left(0\right)=1$  

$f\left(1\right)=1$  

$f\left(2\right)=1$  

$f\left(3\right)=3-1=2$  

$f\left(4\right)=4-1=3$  

 

$\pi -2\le 2$  

$f\left(\pi -2\right)=1$  

 

$\sqrt{2}+1>2$  

$f\left(\sqrt{2}+1\right)=\sqrt{2}+1-1=\sqrt{2}$