package Others;

import java.util.ArrayList;

/** @author Dekas Dimitrios */
public class WorstFit {
 private static final int NO_ALLOCATION =
 -255; // if a process has been allocated in position -255,
 // it means that it has not been actually allocated.

 /**
 * Method to find the index of the memory block that is going to fit the given process based on
 * the worst fit algorithm.
 *
 * @param blocks: the array with the available memory blocks.
 * @param process: the size of the process.
 * @return the index of the block that fits, or -255 if no such block exists.
 */
 private static int findWorstFit(int[] blockSizes, int processSize) {
 int max = -1;
 int index = -1;
 for (int i = 0;
 i < blockSizes.length;
 i++) { // Find the index of the biggest memory block available.
 if (blockSizes[i] > max) {
 max = blockSizes[i];
 index = i;
 }
 }
 // If the biggest memory block cannot fit the process, return -255 as the result
 if (processSize > blockSizes[index]) {
 return NO_ALLOCATION;
 }
 return index;
 }

 /**
 * Method to allocate memory to blocks according to the worst fit algorithm. It should return an
 * ArrayList of Integers, where the index is the process ID (zero-indexed) and the value is the
 * block number (also zero-indexed).
 *
 * @param sizeOfBlocks: an int array that contains the sizes of the memory blocks available.
 * @param sizeOfProcesses: an int array that contains the sizes of the processes we need memory
 * blocks for.
 * @return the ArrayList filled with Integers repressenting the memory allocation that took place.
 */
 static ArrayList<Integer> worstFit(int[] sizeOfBlocks, int[] sizeOfProcesses) {
 // The array list responsible for saving the memory allocations done by the worst-fit algorithm
 ArrayList<Integer> memAlloc = new ArrayList<>();
 // Do this for every process
 for (int processSize : sizeOfProcesses) {
 int chosenBlockIdx =
 findWorstFit(
 sizeOfBlocks, processSize); // Find the index of the memory block going to be used
 memAlloc.add(chosenBlockIdx); // Store the chosen block index in the memAlloc array list
 if (chosenBlockIdx
 != NO_ALLOCATION) { // Only if a block was chosen to store the process in it,
 sizeOfBlocks[chosenBlockIdx] -= processSize; // resize the block based on the process size
 }
 }
 return memAlloc;
 }

 /**
 * Method to print the memory allocated.
 *
 * @param memAllocation: an ArrayList of Integer representing the memory allocation done by the
 * worstFit method.
 */
 public static void printMemoryAllocation(ArrayList<Integer> memAllocation) {
 System.out.println("Process No.\tBlock No.");
 System.out.println("===========\t=========");
 for (int i = 0; i < memAllocation.size(); i++) {
 System.out.print(" " + i + "\t\t");
 if (memAllocation.get(i) != NO_ALLOCATION) System.out.print(memAllocation.get(i));
 else System.out.print("Not Allocated");
 System.out.println();
 }
 }
}