11a.c

//Page Replacement FIFO
#include <stdio.h>
int main(int argc, char const *argv[])
{
  int i, j, n, a[50], frame[10], no, k, avail, count = 0;
  printf("Enter the no. of pages: ");
  scanf("%d", &n);
  printf("\n");
  printf("Enter the page no.: ");
  for (i = 1; i <= n; i++)
    scanf("%d", &a[i]);
  printf("\n");
  printf("Enter the number of frames: ");
  scanf("%d", &no);
  printf("\n");
  for (i = 0; i < no; i++)
    frame[i] = -1;
  j = 0;
  printf("Ref string\tpage frames\n");
  for (i = 1; i <= n; i++)
  {
    printf("%d\t\t", a[i]);
    avail = 0;
    for (k = 0; k < no; k++)
      if (frame[k] == a[i])
        avail = 1;
    if (avail == 0)
    {
      frame[j] = a[i];
      j = (j + 1) % no;
      count++;
      for (k = 0; k < no; k++)
        printf("%d\t", frame[k]);
    }
    printf("\n");
  }
  printf("Page Fault = %d", count);
  printf("\n");
  return 0;
}