Java - Permutation of ArrayList elements (Integer) - Can't get it to work properly

Question

I\'ve been looking around quite a bit to solve my issue. I got many problems solved but this one is still haunting me :S It\'s been a long time I haven\'t touch Java program

Answer 1

You can try Recursion to solve this issue:

public static void printPermutations(int[] n, int[] Nr, int idx) {
    if (idx == n.length) {  //stop condition for the recursion [base clause]
        System.out.println(Arrays.toString(n));
        return;
    }
    for (int i = 0; i <= Nr[idx]; i++) { 
        n[idx] = i;
        printPermutations(n, Nr, idx+1); //recursive invokation, for next elements
    }
}

More info can be had from this link: Combinatorics: generate all “states” - array combinations

You can replicate the same logic here as well.