page_replacement_visualizer.py

def fifo_page_replacement(reference_string, frames):
    memory = []
    page_faults = 0

    print("\n--- FIFO (First In First Out) ---")
    print("Page\tMemory Frames\t\tPage Fault?")
    print("----\t-------------\t\t-----------")

    for page in reference_string:
        fault_status = "No"
        if page not in memory:
            page_faults += 1
            fault_status = "Yes"
            if len(memory) == frames:
                memory.pop(0)
            memory.append(page)


        mem_str = ' '.join(map(str, memory))
        print(f"{page}\t[{mem_str:<15}]\t{fault_status}")

    return page_faults


def lru_page_replacement(reference_string, frames):
    memory = []
    page_faults = 0

    print("\n--- LRU (Least Recently Used) ---")
    print("Page\tMemory Frames\t\tPage Fault?")
    print("----\t-------------\t\t-----------")

    for page in reference_string:
        fault_status = "No"
        if page not in memory:
            page_faults += 1
            fault_status = "Yes"
            if len(memory) == frames:
                memory.pop(0)
            memory.append(page)
        else:
            memory.remove(page)
            memory.append(page)

        mem_str = ' '.join(map(str, memory))
        print(f"{page}\t[{mem_str:<15}]\t{fault_status}")

    return page_faults



if __name__ == "__main__":
    frames_input = input("Enter the number of memory frames : ")
    frames = int(frames_input)
    if frames < 0 or frames > 8:
      print("Enter valid number of frames")

    pages_input = input("Enter the reference string : ")

    reference_string = [int(p) for p in pages_input.split()]
    if len(reference_string) == 0 or len(reference_string)>15:
      print("Enter valid reference string with less than 15 pages")


    print(f"\nReference String: {reference_string}")
    print(f"Number of Frames: {frames}")


    fifo_faults = fifo_page_replacement(reference_string, frames)
    lru_faults = lru_page_replacement(reference_string, frames)


    print("\n\n--- Final Page Fault Count ---")
    print(f"FIFO Algorithm Total Page Faults: {fifo_faults} ")
    print(f"LRU Algorithm Total Page Faults:  {lru_faults} ")