/*Program to implement page replacement using LFU algorithm*/#include<stdio.h>int i,j=1,s,k,l,re[30],p[10],ch,no,nr,c,a1=0,a,line=6,nk;struct{

int st,l,ps,pos;}opr;main(){

clrscr();printf("Enter length of reference string:");scanf("%d",&nr);printf(" Enter reference string:");for(i=1;i<=nr;i++)scanf("%d",&re[i]);printf("\n Enter number of frames:");scanf("%d",&no);clrscr();for(i=1;i<=no;i++)p[i]=-1;opr.st=100;for(i=1;i<=nr;i++){

a1=0;opr.st=100;opr.pos=100;for(c=1;c<=no;c++)if(re[i]==p[c])a1++;if(a1==0){

if(j<=no){

p[j]=re[i];j++;

}else{

for(k=1;k<=no;k++){

a=0;for(ch=i-1;ch>0;ch--){

if(p[k]==re[ch]){

a++;nk=ch;

}}if(a>1){

if(opr.st>a){

1

opr.st=a;opr.ps=k;

}elseif(opr.st==a){

if(opr.pos>ch)opr.ps=k;

}}elseif(a==1){

if(opr.pos>nk){

opr.pos=nk;opr.ps=k;opr.st=a;

}}

}p[(opr.ps)]=re[i];

}}display(no,p,i);

}printf("\n");getch();

}

display(int no,int p[],int i){

int k;if(i==1){

printf("\t\t\t");for(k=1;k<=no;k++)printf("_ _");

}printf("\n%d",re[i]);gotoxy(25,line++);for(k=1;k<=no;k++){

printf("|");printf("_");if(p[k]!=-1)printf("%d",p[k]);elseprintf(" ");printf("_");

}printf("|");

}

2