SPOS - First in First Out [FIFO] Program

import java.io.*;

public class FIFO {

public static void main(String[] args) throws IOException

{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

int frames, pointer = 0, hit = 0, fault = 0,ref_len;

int buffer[];

int reference[];

int mem_layout[][];

System.out.println("Please enter the number of Frames: ");

frames = Integer.parseInt(br.readLine());

System.out.println("Please enter the length of the Reference string: ");

ref_len = Integer.parseInt(br.readLine());

reference = new int[ref_len];

mem_layout = new int[ref_len][frames];

buffer = new int[frames];

for(int j = 0; j < frames; j++)

buffer[j] = -1;

System.out.println("Please enter the reference string: ");

for(int i = 0; i < ref_len; i++)

{

reference[i] = Integer.parseInt(br.readLine());

}

System.out.println();

for(int i = 0; i < ref_len; i++)

{

int search = -1;

for(int j = 0; j < frames; j++)

{

if(buffer[j] == reference[i])

{

search = j;

hit++;

break;

}

}

if(search == -1)

{

buffer[pointer] = reference[i];

fault++;

pointer++;

if(pointer == frames)

pointer = 0;

}

for(int j = 0; j < frames; j++)

mem_layout[i][j] = buffer[j];

}

for(int i = 0; i < frames; i++)

{

for(int j = 0; j < ref_len; j++)

System.out.printf("%3d ",mem_layout[j][i]);

System.out.println();

}

System.out.println("The number of Hits: " + hit);

System.out.println("Hit Ratio: " + (float)((float)hit/ref_len));

System.out.println("The number of Faults: " + fault);

}

}