Problem $1$: Parameter Passing Exercise $[20$ pts$]$

Consider the following pseudocode:

$1$ x $=1,$ y $=3,$ z $=5$

$2$ function foo $($a $,$ b $)$:

$3$ x $=$ x $+$ b ;

$4$ z $=$ x $+$ y ;

$5$ a $=$ a $-$ z ;

$6$ y $=$ a $-$ x $+$ b ;

$1[16$pts$]$ For each of the cases below, write down the values of x$,$ y$,$ and z after the

following calls to foo$().$ If necessary, assume that output arguments are copied back to

parameters in the left$-$to$-$right order.

$($a$)$ foo$($x$,$y$)$ where all parameters are passed by value.

$($b$)$ foo$($x$,$z$)$ where all parameters are passed by reference.

$($c$)$ foo$($y$,$z$)$ where all parameters are passed by value$-$result.

$($d$)$ foo$($z$,$z$)$ where all parameters are passed by reference.

$2[4$pts$]$ Passed$-$by$-$result parameter passing scheme is not applicable for the above pro$-$

gram $$ justify this statement with proper example