what is a C code that solves these problems?

In the following questions, f$1(),$ f$2(),$ f$3()$ are thread functions. Use semaphores to obtain the result as requested in each equation.

The solution code MUST contain PThreads and Semaphores.

$[1]$

void $*$f$1($void $*$arg$)$

$\{$

printf$($first$)$;

$\}$

void $*$f$2($void $*$arg$)$

$\{$

printf$($Second$)$;

$\}$

void $*$f$3($void $*$arg$)$

$\{$

printf$($Third$)$;

$\}$

The required result on screen monitor is

First

Second

Third

$[2]$

$\frac{?}{?}*$ global variables$\frac{*}{}$

int $m=0$;

int $n=0$;

void $*$f$1($void $*$arg$)$

$\{$

m $=10$;

$\}$

void $*$f$2($void $*$arg$)$

$\{$

n $=14$;

$\}$

void $*$f$3($void $*$arg$)$

$\{$

int r;

r $=$ m $+$ n;

printf$($r $=\%$d$,$ r$)$;

$\}$

The required result on screen monitor is

$r=24$

$[3]$

int a $=0$;

int b $=0$;

int c $=0$;

void $*$f$1($void $*$arg$)$

$\{$

int r;

a $=1$;

r $=$ a $+$ b $+$ c;

printf$($r $=\%$d$,$ r$)$;

$\}$

void $*$f$2($void $*$arg$)$

$\{$

int r;

b $=2$;

r $=$ a $*$ b $*$ c;

printf$($r $=\%$d$,$ r$)$;

$\}$

void $*$f$3($void $*$arg$)$

$\{$

int r;

c $=6$;

r $=$ c $-$ a $-$ b ;

printf$($r $=\%$d$,$ r$)$;

$\}$

$**$ The required result on screen monitor is

$r=9$

$r=12$

$r=3$

$**$ The order of the output is not important. So$,$ this output is also valid

$r=12$

$r=3$

$r=9$