static final int size = 10;

static final int h = size / 2;

public static void main(String[] args) {

doCalculationOne(createArray());

doCalculationTwo(createArray());

}

private static float[] createArray () {

float[] arr = new float[size];

Arrays.fill(arr, 1); // вместо цикла for

return arr;

}

private static void doCalculationOne(float[] arr) {

System.out.println(Arrays.toString(arr));

long a = System.currentTimeMillis();

for (int i = 0; i < arr.length; i++) {

arr[i] = (float)(arr[i] * Math.sin(0.2f + i / 5) * Math.cos(0.2f + i / 5) * Math.cos(0.4f + i / 2));

}

System.out.println(Arrays.toString(arr));

System.out.println("The total time for one array is ");

System.out.println(System.currentTimeMillis() - a);

}

private static void doCalculationTwo(float[] arr) {

System.out.println(Arrays.toString(arr));

float[] arrOne = new float[h];

float[] arrTwo = new float[h];

long b = System.currentTimeMillis();

System.arraycopy(arr, 0, arrOne, 0, h);

System.arraycopy(arr, h, arrTwo, 0, h);

System.out.println(Arrays.toString(arrOne));

System.out.println(Arrays.toString(arrTwo));

Thread calcOne = new Thread(new Runnable() {

@Override

public void run() {

for (int i = 0; i < arrOne.length; i++) {

arrOne[i] = (float)(arrOne[i] * Math.sin(0.2f + i / 5) * Math.cos(0.2f + i / 5) * Math.cos(0.4f + i / 2));

}

}

});

calcOne.start();

Thread calcTwo = new Thread(new Runnable() {

@Override

public void run() {

for (int i = 0; i < arrTwo.length; i++) {

arrTwo[i] = (float) (arrTwo[i] * Math.sin(0.2f + (i+h) / 5) * Math.cos(0.2f + (i+h) / 5) * Math.cos(0.4f + (i+h) / 2));

}

}

});

calcTwo.start();

try {

calcOne.join();

calcTwo.join();

} catch (InterruptedException e) {

e.printStackTrace();

}

System.arraycopy(arrOne, 0, arr, 0, h);

System.arraycopy(arrTwo, 0, arr, h, h);

System.out.println(Arrays.toString(arr));

System.out.println("The total time for two arrays is ");

System.out.println(System.currentTimeMillis() - b);

}

}