1
class Solution {
2
  public int[][] generateMatrix(int n) {
3
    int startingRow = 0;
4
    int endingRow = n - 1;
5
    int startingCol = 0;
6
    int endingCol = n - 1;
7

8
    int total = n * n;
9
    int element = 1;
10
    int[][] matrix = new int[n][n];
11

12
    while (element <= total) {
13

14
      for (int i = startingCol; element <= total && i <= endingCol; i++) {
15
        matrix[startingRow][i] = element;
16
        element++;
17
      }
18
      startingRow++;
19

20
      for (int i = startingRow; element <= total && i <= endingRow; i++) {
21
        matrix[i][endingCol] = element;
22
        element++;
23
      }
24
      endingCol--;
25

26
      for (int i = endingCol; element <= total && i >= startingCol; i--) {
27
        matrix[endingRow][i] = element;
28
        element++;
29
      }
30
      endingRow--;
31

32
      for (int i = endingRow; element <= total && i >= startingRow; i--) {
33
        matrix[i][startingCol] = element;
34
        element++;
35
      }
36
      startingCol++;
37
    }
38

39
    return matrix;
40
  }
41
}