First In First Out (FIFO) 1

FIFO is the simplest technique for replacing pages in a frame. It decides when a page fault occurs then which frames are to be replaced.  Create a program to counts the number of page fault occurs when an input reference string is given.  The input contains integer values for a number of pages in a queue, sequence of reference strings and frame size. The output should display the total number of page faults.

Note: Text in Bold corresponds to the input 
Sample Input and Output
Enter No. of Pages:
6
Enter values of Reference String :
1
2
2
3
1
4
Enter no. of frames:
3
Total Page Faults 4

Answer:

#include<stdio.h>
int main()
{
    int i,j,n,a[30],no,k,av,count=0,frame[10];
    printf("Enter No. of Pages:\n");
    scanf("%d",&n);
    printf("Enter  values of Reference String :\n");
    for(i=0;i<n;i++){
        scanf("%d",&a[i]);
    }
    printf("Enter no. of frames:\n");
    scanf("%d",&no);
    for(i=0;i<no;i++)
    {
        frame[i]=-1;
    }
    for(i=0;i<n;i++)
    {
        av=0;
        for(k=0;k<no;k++)
        if(frame[k]==a[i])
            av=1;
        if(av==0)
        {
            frame[j]=a[i];
            j=(j+1)%no;
            count++;
        }
    }
    printf("Total Page Faults %d",count);
    return 0;
}