Question

I need help with this question in JAVA. I need the code, the UML diagram and the pseudocode Do a recursive method that return every possible k permutations of the String non-zeros number given Sample input : "123" , 2 output : "1-2", "1-3", "2-3", "2-1", "3-1", "3-2"

Answer 1

I am providing JAVA code for k possible permutations, as the input can be a digit or letter so I have not set any data type for that.

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import java.util.Arrays;

public class Combination {
    public static void main(String[] args){
        String[] arr = {"1","2","3"};
        combinations2(arr, 3, 0, new String[3]);
    }

    static void combinations2(String[] arr, int len, int startPosition, String[] result){
        if (len == 0){
            System.out.println(Arrays.toString(result));
            return;
        }       
        for (int i = startPosition; i <= arr.length-len; i++){
            result[result.length - len] = arr[i];
            combinations2(arr, len-1, i+1, result);
        }
    }       
}

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The code above takes string array, where I have added 1,2,3 as you gave in the example, this will now print all the required permutation and combinations.

With the code, why there is need of pseudocode. If any doubt please comment. Please Upvote

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