#include <stdio.h>

int main(void) {
    int frames = 3;
    int page_refs[] = {1, 2, 3, 4, 1, 2, 5, 1, 2};
    int num_refs = 9;
    int mem[3];
    int count = 0;
    int hit_count = 0;
    printf("Demonstrating FIFO page replacement\n");
    for (int i = 0; i < num_refs; ++i) {
        int pg = page_refs[i];
        int found = 0;
        for (int k = 0; k < count; ++k) {
            if (mem[k] == pg) {
                found = 1;
                break;
            }
        }
        if (found) {
            hit_count++;
            printf("page %d : hit, memory contains", pg);
        } else {
            printf("page %d : miss, memory contains", pg);
            if (count < frames) {
                mem[count] = pg;
                count++;
            } else {
                for (int k = 0; k < frames - 1; ++k) {
                    mem[k] = mem[k + 1];
                }
                mem[frames - 1] = pg;
            }
        }
        for (int k = 0; k < count; ++k) {
            printf(" %d", mem[k]);
        }
        printf("\n");
    }
    printf("Hits = %d out of %d\n", hit_count, num_refs);
    return 0;
}