Generate all the possible k-ary strings of length and digit upto k

You have been given an integer n that corresponds to the length of the array and k which corresponds to the digit value possible in the array. The task is to print all the possible strings using those k values of length n. the array can consist only value digits up to k.

Java Solution:

public class AllStringsKAry {

	public static void main(String[] args) {
		int n = 3;
		int k = 2;
		int[] arr = new int[n];
		GenerateAllStringKAry(n, arr, k);
	}

	private static void GenerateAllStringKAry(int n,int[] arr, int k) {
		if(n<1) {
			for(int i=0;i<arr.length;i++) {
				System.out.print(arr[i]);
			}
			System.out.println();
		}
		else {
			for(int i=0;i<=k;i++) {
				arr[n-1]=i;
				GenerateAllStringKAry(n-1, arr, k);
			}
			
		}
			
	}

}

The time complexity of the above solution is O(k^n).

output:

000
100
200
010
110
210
020
120
220
001
101
201
011
111
211
021
121
221
002
102
202
012
112
212
022
122
222