Sem 4 Operating System (OS) : LRU page replacement Java Code / Program

Given below is the Java program for LRU page replacement policy. import java.util.*; class LRU { static int check1(int p[],int pf[],int n,int s) { int count[]=new int[s]; for(int i=0;i<s;++i) { int j=n; while(j>=0 && p[j]!=pf[i]) { ++count[i]; --j; } } int max=count[0]; int pos=0; for(int i=1;i<s;++i) { if(count[i]>max) { max=count[i]; pos=i; } } return pos; } static boolean check(int p[],int n,int x) { for(int i=0;i<n;++i) { if(p[i]==x) return true; } return false; } public static void main(String args[]) { Scanner scr=new Scanner(System.in); System.out.println("Enter the number of page entries"); int n=scr.nextInt(); int fault=0,hit=0; int p[]=new int[n]; System.out.println("Enter the pages "); for(int i=0;i<n;++i) p[i]=scr.nextInt(); System.out.print("The page table entries are "); for(int i=0;i<n;++i) System.out.print(" "+p[i]); System.out.println(); int s=3; System.out.println("Do you wish to set a the number of page frames?(1=yes/0=no)"); int ch=scr.nextInt(); if(ch==1) { System.out.println("Enter the number of page frames "); s=scr.nextInt(); System.out.println("The number of page frames set to "+s); } else System.out.println("The default number of page frames are "+s); int pf[]=new int[s]; for(int i=0;i<s;++i) pf[i]=-1; int d=0; int choice=0; for(int i=0;i<n;++i) { if(check(pf,s,p[i])) { ++hit; for(int j=0;j<s && pf[j]!=-1;++j) System.out.print(pf[j]+" "); System.out.print("H\n"); } else { ++fault; if(fault<=s) { pf[d]=p[i]; ++d; } else { choice=check1(p,pf,i-1,s); pf[choice]=p[i]; } for(int j=0;j<s && pf[j]!=-1;++j) System.out.print(pf[j]+" "); System.out.print("F\n"); } } System.out.println("Number of page Hits= "+hit+"\nNumber of page Faults= "+fault); } }