[leetcode]Spiral Matrix II

似曾相识。。。

public class Solution {

    public int[][] generateMatrix(int n) {

        int cnt = 1;

        int top = 0;

        int bottom = n-1;

        int left = 0;

        int right = n-1;

        int[][] r = new int[n][n];

        while (cnt <= n* n)

        {

            for (int i = left; i <= right; i++)

                r[top][i] = cnt++;

            top++;

            for (int i = top; i <= bottom; i++)

                r[i][right] = cnt++;

            right--;

            for (int i = right; i >= left; i--)

                r[bottom][i] = cnt++;

            bottom--;

            for (int i = bottom; i >= top; i--)

                r[i][left] = cnt++;

            left++;

        }

        return r;

    }

}