Given an integer

*n*, generate a square matrix filled with elements from 1 to*n*2 in spiral order.
For example,

Given

You should return the following matrix:Given

*n*=`3`

,[ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ]

**Understand the problem:**

The problem gives an integer n, generate a square matrix filled in spiral order.

For example, n = 0, return empty matrix.

For n = 1, return [1]

For n = 2, return [ [1, 2]

[4, 3]

]

For n = 3, return the matrix as shown in the problem.

So the solution would be the very closed to the Spiral matrix I.

**Solution:**

public class Solution { public int[][] generateMatrix(int n) { int[][] result = new int[n][n]; if (n == 0) { return result; } int start = 1; int row = 0; int col = 0; while (n > 0) { if (n == 1) { result[row][col] = start; break; } // Move right for (int i = 0; i < n - 1; i++) { result[row][col++] = start++; } // Move down for (int i = 0; i < n - 1; i++) { result[row++][col] = start++; } // Move left for (int i = 0; i < n - 1; i++) { result[row][col--] = start++; } // Move up for (int i = 0; i < n - 1; i++) { result[row--][col] = start++; } row++; col++; n -= 2; } return result; } }

## No comments:

## Post a Comment