#include <stdio.h>
#include <stdint.h>

int main(void) {
    const uint8_t page_table[4] = {3, 7, 5, 2};
    const uint8_t virtual_addrs[4] = {21, 0, 32, 48};
    for (int i = 0; i < 4; ++i) {
        uint8_t va = virtual_addrs[i];
        uint8_t vpn = va >> 4;
        uint8_t offset = va & 0x0F;
        uint8_t pfn = page_table[vpn];
        uint8_t pa = (uint8_t)((pfn << 4) | offset);
        printf("VA %u (VPN %u, offset %u) -> PA %u (PFN %u)\n",
               va, vpn, offset, pa, pfn);
    }
    return 0;
}