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labwork [276]
3 years ago
12

What are the three main purposes of an operating system? Explain how the old mainframe computers were different from the compute

rs we have today.
Computers and Technology
1 answer:
lbvjy [14]3 years ago
3 0

Answer:(1) To manage the computer's resources, which includes central processing unit, memory, disk drives, and printers, (2) To establish a user interface

(3)To execute and provide services for applications software.

The old mainframe computers have

(1) low memory sizes

(2) slower connectivity speed

(3) Larger sizer

(4) low sophistication.

Explanation: Operating system is a system software that manages the computer resources,helps to establish user interface and it helps to provide services for application softwares.

Operating system software includes WINDOWS X,WINDOWS 7,WINDOWS 8,LINUX,etc.

Mainframe computers are computers used by large multinational companies for processing bulk data. Old mainframe computers were produced by IBM(INTERNATIONAL BUSINESS MACHINE) in the year 1952 they are classed two scientific and commercial mainframe computers with different information although they had some incompatibilities. Old mainframe computers are large in size with low processing speed, sophistication and storage compared to present day system.

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andreev551 [17]

Answer:

public void trimToSize() {

modCount++;

if (size < elementData.length) {

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? EMPTY_ELEMENTDATA

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Now, the running time for copyOf() function is O(N) where N is the size/capacity of the ArrayList. Hence, the time complexity of trimToSize() function is O(N).

Hence, the running time of building an N-item ArrayList is O(N^2).

Please find the sample code below.

CODE

==================

import java.util.ArrayList;

public class Driver {

  public static void main(String[] args) throws Exception{

      int N = 100000;

      ArrayList<Integer> arr = new ArrayList<>(N);

     

      long startTime = System.currentTimeMillis();

      for(int i=0; i<N; i++) {

          arr.add(i);

          arr.trimToSize();

      }

      long endTime = System.currentTimeMillis();

      double time = (endTime - startTime)/1000;

      System.out.println("Total time taken = " + time + " seconds.");

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Explanation:

5 0
3 years ago
What is the oldest malware victor
arsen [322]

Answer:

The oldest malware vector was emails.

Explanation:

Websites were not widespread early on into the internet, however it was very easy to have a virus that uses an email contact list, where it can send itself to other email addresses and spread.

7 0
3 years ago
What is output? c = 1 sum = 0 while (c &lt; 10): c = c + 3 sum = sum + c print (sum)
Valentin [98]

Answer:

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p.s. why did you not run the program yourself?

3 0
3 years ago
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