Number pattern problem using Java

Question

Got this question in a test.

Display the following number pattern using Java.

User inputs number of rows. For example 3

1112
3222
3334

For 5

111112
322222
333334
544444
555556

and so on.

This is the solution I came up with:

 public static void NumberPattern(int n) {
 int myarray[][] = new int[n][n + 1];
 int i;
 int j;
 for (i = 0; i < 1; i++) //first row
 {
 for (j = 0; j < n; j++) 
 {
 myarray[i][j] = i + 1;
 }
 myarray[i][n] = i + 2;
 }
 for (i = 1; i < myarray.length; i++) 
 {
 if (i % 2 != 0) //odd rows
 {
 j = 1;
 myarray[i][0] = i + 2;
 while (j <= n)
 {
 myarray[i][j] = i + 1;
 j++;
 }
 j = 1;
 }
 if (i % 2 == 0) //even rows
 {
 j = 0;
 while (j < n) {
 myarray[i][j] = i + 1;
 j++;
 }
 myarray[i][n] = i + 2;
 j = 0;
 }
 }
 printArray(myarray);
}
 public static void printArray(int n[][])
 {
 System.out.println("The Pattern is:");
 for (int[] array : n) {
 for (int v : array) {
 System.out.print(" " + v);
 }
 System.out.println();
 }
 }

Is there a better way of solving this problem with only one for loop?

Answer 1

Since all you've been asked is to display output, a single simple nesting of two for loops without arrays should work just fine. Note that in all cases, you know in advance prior to performing a loop how many times the loop will iterate, and in this situation a for loop is cleaner than a while loop (though of course both would work):

// note that method namess should begin with a lower-case letter
public static void numberPattern(int rows) {
 for (int row = 0; row < rows; row++) {
 for (int col = 0; col < rows + 1; col++) {
 int number = 0;
 if (row % 2 == 0) {
 number = col < rows ? row + 1 : row + 2;
 } else {
 number = col == 0 ? row + 2 : row + 1;
 }
 System.out.print(number);
 }
 System.out.println();
 }
}

If you need to store the numbers to be used elsewhere, then yes, put them into an array.