w3resource

Java Exercises: Sum of all the elements from all possible subsets of a set formed by first n natural numbers

Java Basic: Exercise-193 with Solution

Write a Java program that accept an integer and find the sum of all the elements from all possible subsets of a set formed by first n natural numbers.

Sample Solution:

Java Code:

import java.util.Scanner;
public class Solution {
 public static void main(String[] args) {
  Scanner in = new Scanner(System.in);
  System.out.print("Input a positive integer: ");
  int n = in .nextInt();
  int result = (n * (n + 1) / 2) * (1 << (n - 1));
  System.out.print("Sum of subsets of n is : " + result);
 }
}

Sample Output:

Input a positive integer:  25
Sum of subsets of n is : 1157627904

Flowchart:

Flowchart: Java exercises: Sum of all the elements from all possible subsets of a set formed by first n natural numbers

Java Code Editor:

Company:  Bloomberg

Contribute your code and comments through Disqus.

Previous: Write a Java program to rearrange the alphabets in the order followed by the sum of digits in a given string containing uppercase alphabets and integer digits (from 0 to 9).
Next: Write a Java program to find the all positions of a given number in a given matrix. If the number not found print ("Number not found!").

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.

Java: Tips of the Day

How to remove leading zeros from alphanumeric text?

Regex is the best tool for the job; what it should be depends on the problem specification. The following removes leading zeroes, but leaves one if necessary (i.e. it wouldn't just turn "0" to a blank string).

s.replaceFirst("^0+(?!$)", "")

The ^ anchor will make sure that the 0+ being matched is at the beginning of the input. The (?!$) negative lookahead ensures that not the entire string will be matched.

Test harness:

String[] in = {
    "01234",         // "[1234]"
    "0001234a",      // "[1234a]"
    "101234",        // "[101234]"
    "000002829839",  // "[2829839]"
    "0",             // "[0]"
    "0000000",       // "[0]"
    "0000009",       // "[9]"
    "000000z",       // "[z]"
    "000000.z",      // "[.z]"
};
for (String s : in) {
    System.out.println("[" + s.replaceFirst("^0+(?!$)", "") + "]");
}

Ref: https://bit.ly/2Qdcl8a