CODEWITHSUNDEEP
java
AKIWEB
AKIWEB

Reputation: 19612

Combinations of alphabet in Char array

I have a char array of A, B, C and I want to print the output as:

A,B,C,AB,AC,BC,ABC

Any suggestions will be appreciated...

public class CharArray {
    public static void main(String[] args) {
        char alpha[] = {'A', 'B', 'C'};
        for(char s : alpha) {
                    //what to do now
        }

    }

}

Upvotes: 3

Views: 1817

Answers (2)

Louis Hartmetz
Louis Hartmetz

Reputation: 36

Another option to consider is in guava (an open source java library by google).

Sets (a set utilities class)

/**   Returns the set of all possible subsets of set. For example, powerSet(ImmutableSet.of(1, 2)) returns the set {{}, {1}, {2}, {1, 2}}... */
        public static <E> Set<Set<E>> powerSet(Set<E> set)

http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/collect/Sets.html#powerSet(java.util.Set)

Upvotes: 0

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 726599

This prints combinations, as in your example, not permutations, as in the title of the question.

char alpha[] = {'A', 'B', 'C'};
for (int m = 1 ; m != 1<<alpha.length ; m++) {
    for (int i = 0 ; i != alpha.length ; i++) {
        if ((m & (1<<i)) != 0) {
            System.out.print(alpha[i]);
        }
    }
    System.out.println();
}

Upvotes: 6

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