Problem $4$: Nested Scopes and Links

Consider the following pseudo$-$code, assuming nested subroutines and static scoping:

main$()\{$

a$\}=2$

b $=3$;

c $=4$;

f$1($x$)\{$

b $=5$

f$2($y$)\{$

c $=6$;

f$3($z$)\{$

a $=7$;

f$4($w$)\{$

return a $*$ b $+$c$*$x $*$ y $-$ z $+$ w;

$\}$

return f$4($y$+$z$)+$ c;

$\}$

return f$3($x $*$ y$)+$ b;

$\}$

return f$2($x $+$ b$)+$ a;

$\}$

result $=$ f$1($a$+$c$)$;

print result;

$\}$

What does the program print?Provide a step$-$by$-$step breakdown of the calculations.

Draw a diagram of the runtime stack when function $f{4}_{?}$ has been called for the last

time. For each frame, show the static and dynamic links.

Refer to the runtime stack, briefly explain how function $f_{?}$ accesses variables $a_{,}{b}_{?},$ and

c$.$