FIFO Page Replacement Algorithm Implementation in C

fifo.c

#include<stdio.h>

void fifo(int string[20],int n,int size)//n no frames
{
    //Creating array for block storage
    int frames[n];
    //Initializing each block with -1
    for (int i=0;i<n;i++)
        frames[i]=-1;

    //Index to insert element
    int index=0;
	int i,j;
    //Counters
    int page_miss=0;
    int page_hits=0;

    //Traversing each symbol in fifo
    for (i=0;i<size;i++)
    {
        //int symbol=string[i];//7,
        int flag=0;
        for(j=0;j<n;j++)
        {
            if (string[i]==frames[j])
            {
                flag=1;
                break;
            }
        }
        if (flag==1)
        {
            page_hits+=1;
        }
        else
        {
            //replacment for =>index=(index+1)%n (only for understanding)
            if(index<2){
                frames[index]=string[i];
                page_miss+=1;
                index++;
            }else if(index==2){
                frames[index]=string[i];
                page_miss+=1;
                index=0;
            }
          
        }
    }
    printf("\nPage hits: %d",page_hits);
    printf("\nPage misses: %d",page_miss);
}

//Main function
int main(void)
{
    int string[]={7,0,1,2,0,3,0,4,2};
    int no_frames=3;
    //gets the size of string[]
    
    //if we have 4 int values that means 4*4=16 to sum it up from 4 bytes to one
    //byte(1 int is 4 but we need only 1 for count) we divide it with one int
    //4*4=16 then 16/4=4(we got size)
    //1*4=4 then 4/4=1
    int size=sizeof(string) / sizeof(int);//int size is 4 

    printf("%d",size);
    fifo(string,no_frames,size);
    return 0;
}