Skip to content
Related Articles

Related Articles

Finding all subsets of a given set in Java
  • Difficulty Level : Medium
  • Last Updated : 31 Jan, 2020

Problem: Find all the subsets of a given set.

S = {a, b, c, d}
{}, {a} , {b}, {c}, {d}, {a,b}, {a,c},
{a,d}, {b,c}, {b,d}, {c,d}, {a,b,c}, 
{a,b,d}, {a,c,d}, {b,c,d}, {a,b,c,d}

The total number of subsets of any given set is equal to 2^ (no. of elements in the set). If we carefully notice it is nothing but binary numbers from 0 to 15 which can be shown as below:

0011{a, b}
0101{a, c}
0110{b, c}
0111{a, b, c}
1001{a, d}
1010{b, d}
1011{a, b, d}
1100{c, d}
1101{a, c, d}
1110{b, c, d}
1111{a, b, c, d}

Starting from right, 1 at ith position shows that the ith element of the set is present as 0 shows that the element is absent. Therefore, what we have to do is just generate the binary numbers from 0 to 2^n – 1, where n is the length of the set or the numbers of elements in the set.

// A Java program to print all subsets of a set
class Main
    // Print all subsets of given set[]
    static void printSubsets(char set[])
        int n = set.length;
        // Run a loop for printing all 2^n
        // subsets one by one
        for (int i = 0; i < (1<<n); i++)
            System.out.print("{ ");
            // Print current subset
            for (int j = 0; j < n; j++)
                // (1<<j) is a number with jth bit 1
                // so when we 'and' them with the
                // subset number we get which numbers
                // are present in the subset and which
                // are not
                if ((i & (1 << j)) > 0)
                    System.out.print(set[j] + " ");
    // Driver code
    public static void main(String[] args)
        char set[] = {'a', 'b', 'c'};


{ }
{ a }
{ b }
{ a b }
{ c }
{ a c }
{ b c }
{ a b c }


Related Post:
Finding all subsets of a Set in C/C++

This article is contributed by Nikhil Tekwani. If you like GeeksforGeeks and would like to contribute, you can also write an article and mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above

Attention reader! Don’t stop learning now. Get hold of all the important mathematical concepts for competitive programming with the Essential Maths for CP Course at a student-friendly price. To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

My Personal Notes arrow_drop_up
Recommended Articles
Page :