gistfile1.txt

import java.util.Arrays; //исключительно для быстрого  вывода результата


public class HelloWorld{

     public static void main(String []args){
         
         // Call task 1
         int testNumber = 100;
         System.out.println("Task1 v1: " + checkBinaryOne(testNumber));
         
        // Call task 1 v2 Optimized
         System.out.println("Task1 v2: " + checkBinaryOneOptimizedVery(testNumber));
         
        // Call task 1 v3  very Optimized
         System.out.println("Task1 v3: " + checkBinaryOneOptimizedVery(testNumber));
        
        // Call task 2
        int[] testArray = { 
            1, 2, 3,
        };
        
         System.out.println("Task2: " + Arrays.toString(reverseArray(testArray)));

     }
     
     
     //task1
     public static int checkBinaryOne(int number) {
         
         int sum = 0;
         String binaryText =  Integer.toBinaryString(number);
         System.out.println("debug bin:" + binaryText);

        for (int i = 0; i < binaryText.length(); i++) {
            if (binaryText.charAt(i) == '1') {
                sum++;
            }
        }
        
         
    
         return sum ;
     }
     
    //task1 v2
     public static int checkBinaryOneOptimizedVery(int number) {
  
        number = number - ((number >>> 1) & 0x55555555);
        number = (number & 0x33333333) + ((number >>> 2) & 0x33333333);
        return (((number + (number >>> 4)) & 0x0F0F0F0F) * 0x01010101) >>> 24;

     }
     
        //task1 v3
     public static int checkBinaryOneOptimized(int number) {
  
        int count;
        for (count = 0; number > 0; ++count) {
          number &= number - 1;
        }
        return count;
     }
     
     
    //task1
     public static int[] reverseArray(int[] array) {
         
        int i = 0;
        int j = array.length - 1;
        for (i = 0; i < array.length / 2; i++, j--) {
            int temp = array[i];
            array[i] = array[j];
            array[j] = temp;
         }
        return array;
     }
}