#include<stdio.h>

int waiting =0;

int chairs=n;

boolean wakeup=false;

boolean sleep=false;

semarphore customers=0,baber=1,mutex=1;

void barber()

{

while(true)

{

wait(customers);

wait(mutex);

waiting--;

signal(mutex);

signal(barber);

}

}

 

void customer()

{

do{

wait(mutex);

if(waiting==0)

{

sleep=true;

wakeup=true;

signal(mutex);

}

else if(waiting<n)

{

waiting++;

signal(mutex);

signal(cus