/* Given n>=0, create an array length n*n with the following pattern, shown * here for n=3 : {0, 0, 1, 0, 2, 1, 3, 2, 1} */ public int[] squareUp(int n) { int[] arr = new int[n*n]; if(n == 0) return arr; for(int i = n - 1; i < arr.length; i += n) { for(int j = i; j >= i - i / n; j--) arr[j] = i - j + 1; } return arr; }