mirror of
https://github.com/TheAlgorithms/Java.git
synced 2025-07-19 17:54:42 +08:00
Formatted with Google Java Formatter
This commit is contained in:
github-actions
@ -2,88 +2,95 @@ package Others;
|
||||
|
||||
import java.util.ArrayList;
|
||||
|
||||
/**
|
||||
* @author Dekas Dimitrios
|
||||
*/
|
||||
/** @author Dekas Dimitrios */
|
||||
public class BestFit {
|
||||
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.
|
||||
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 maximum valued element of an array filled with positive integers.
|
||||
*
|
||||
* @param array: an array filled with positive integers.
|
||||
* @return the maximum valued element of the array.
|
||||
*/
|
||||
private static int findMaxElement(int[] array) {
|
||||
int max = -1;
|
||||
for (int value : array) {
|
||||
if (value > max) {
|
||||
max = value;
|
||||
}
|
||||
}
|
||||
return max;
|
||||
/**
|
||||
* Method to find the maximum valued element of an array filled with positive integers.
|
||||
*
|
||||
* @param array: an array filled with positive integers.
|
||||
* @return the maximum valued element of the array.
|
||||
*/
|
||||
private static int findMaxElement(int[] array) {
|
||||
int max = -1;
|
||||
for (int value : array) {
|
||||
if (value > max) {
|
||||
max = value;
|
||||
}
|
||||
}
|
||||
return max;
|
||||
}
|
||||
|
||||
/**
|
||||
* Method to find the index of the memory block that is going to fit the given process based on the best 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 findBestFit(int[] blockSizes, int processSize) {
|
||||
// Initialize minDiff with an unreachable value by a difference between a blockSize and the processSize.
|
||||
int minDiff = findMaxElement(blockSizes);
|
||||
int index = NO_ALLOCATION; // If there is no block that can fit the process, return NO_ALLOCATION as the result.
|
||||
for(int i=0 ; i < blockSizes.length ; i++) { // Find the most fitting memory block for the given process.
|
||||
if(blockSizes[i] - processSize < minDiff && blockSizes[i] - processSize >= 0) {
|
||||
minDiff = blockSizes[i] - processSize;
|
||||
index = i;
|
||||
}
|
||||
}
|
||||
return index;
|
||||
/**
|
||||
* Method to find the index of the memory block that is going to fit the given process based on
|
||||
* the best 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 findBestFit(int[] blockSizes, int processSize) {
|
||||
// Initialize minDiff with an unreachable value by a difference between a blockSize and the
|
||||
// processSize.
|
||||
int minDiff = findMaxElement(blockSizes);
|
||||
int index =
|
||||
NO_ALLOCATION; // If there is no block that can fit the process, return NO_ALLOCATION as the
|
||||
// result.
|
||||
for (int i = 0;
|
||||
i < blockSizes.length;
|
||||
i++) { // Find the most fitting memory block for the given process.
|
||||
if (blockSizes[i] - processSize < minDiff && blockSizes[i] - processSize >= 0) {
|
||||
minDiff = blockSizes[i] - processSize;
|
||||
index = i;
|
||||
}
|
||||
}
|
||||
return index;
|
||||
}
|
||||
|
||||
/**
|
||||
* Method to allocate memory to blocks according to the best 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> bestFit(int[] sizeOfBlocks, int[] sizeOfProcesses) {
|
||||
// The array list responsible for saving the memory allocations done by the best-fit algorithm
|
||||
ArrayList<Integer> memAlloc = new ArrayList<>();
|
||||
// Do this for every process
|
||||
for(int processSize : sizeOfProcesses) {
|
||||
int chosenBlockIdx = findBestFit(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 allocate memory to blocks according to the best 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> bestFit(int[] sizeOfBlocks, int[] sizeOfProcesses) {
|
||||
// The array list responsible for saving the memory allocations done by the best-fit algorithm
|
||||
ArrayList<Integer> memAlloc = new ArrayList<>();
|
||||
// Do this for every process
|
||||
for (int processSize : sizeOfProcesses) {
|
||||
int chosenBlockIdx =
|
||||
findBestFit(
|
||||
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 bestFit 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();
|
||||
}
|
||||
/**
|
||||
* Method to print the memory allocated.
|
||||
*
|
||||
* @param memAllocation: an ArrayList of Integer representing the memory allocation done by the
|
||||
* bestFit 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();
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user