DynamicArray.java
1.18 KB
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package mior.model;
import mcmas.core.MCMChrono;
import java.util.ArrayList;
import java.util.Arrays;
public class DynamicArray {
private int[] array;
private int length;
public DynamicArray() {
this.array = new int[1024];
}
public void set(int index, int value) {
if (index >= array.length) {
this.array = Arrays.copyOf(array, index << 1); //nearestPowerOfTwo(index + 1));
}
this.length = Math.max(length, index + 1);
this.array[index] = value;
}
public int get(int index) {
return this.array[index];
}
public int[] toArray() {
return Arrays.copyOf(array, length);
}
private int nearestPowerOfTwo(int n) {
final int bitsize = Integer.SIZE;
n--;
for (int i = 1; i <= bitsize >> 1; i <<= 1) {
n = n | (n >> i);
}
return n + 1;
}
public static void main(String[] args) {
MCMChrono c = new MCMChrono("ArrayList");
c.start();
ArrayList<Integer> a = new ArrayList<Integer>();
for (int i = 0; i < 10000000; i++) {
a.add(i);
}
System.out.println(c.stop());
c.start();
DynamicArray b = new DynamicArray();
for (int i = 0; i < 10000000; i++) {
b.set(i, i);
}
System.out.println(c.stop());
}
}