OS/optimal.c at main · harishgovindarajan/OS · GitHub

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   #include<stdio.h>
int main()
{
int no_of_frames,no_of_pages,frames[10],pages[30],temp[10],flag1,flag2,flag3,i,j,k,pos,
max,faults=0;
printf("Enter number of frames:");
scanf("%d",&no_of_frames);
printf("Enter number of pages:");
scanf("%d",&no_of_pages);
printf("Enter page reference string:");
for(i=0;i<no_of_pages;++i){
scanf("%d",&pages[i]);
}
for(i=0;i<no_of_frames;++i){
frames[i]=-1;
}
for(i=0;i<no_of_pages;++i)
 {
 flag1=flag2=0;
for(j=0;j<no_of_frames;++j){
if(frames[j]==pages[i]){
flag1=flag2=1; break;
}
}
if(flag1==0){
for(j=0;j<no_of_frames;++j){
if(frames[j]==-1){
faults++;
frames[j]=pages[i];
flag2=1; break;
}
}
}
if(flag2==0){
flag3=0;
for(j=0;j<no_of_frames;++j)
{ temp[j]=-1;
for(k=i+1;k<no_of_pages;++k){
if(frames[j]==pages[k]){
 temp[j]=k; break;
 }
}
 }
for(j=0;j<no_of_frames;++j){
if(temp[j]==-1){
pos=j; flag3=1;
break;
}
} if(flag3==0){ max=temp[0]; pos=0; for(j=1;j<no_of_frames;++j){ if(temp[j]>max)
{ max=temp[j]; pos=j;
}
}
}
frames[pos]=pages[i]; faults++;
}
printf("\n");
for(j=0;j<no_of_frames;++j){
printf("%d\t",frames[j]);
}
}
printf("\n\nTotal Page Faults=%d",faults);
return 0;
}