Question

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
        }

    }

}

Answer 1

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();
}