Leetcode——顺时针打印矩阵

Leetcode——顺时针打印矩阵

输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字。

示例 1：

输入：matrix = [[1,2,3],[4,5,6],[7,8,9]]
输出：[1,2,3,6,9,8,7,4,5]

示例 2：

输入：matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
输出：[1,2,3,4,8,12,11,10,9,5,6,7]

限制：

0 <= matrix.length <= 100
0 <= matrix[i].length <= 100

代码如下：

class Solution {
    public int[] spiralOrder(int[][] matrix) {
        if(matrix.length == 0) return new int[0];
        int left = 0, right = matrix[0].length - 1, top = 0, bottom = matrix.length - 1, x = 0;
        int[] res = new int[(right + 1) * (bottom + 1)];
        while(true) {
            for(int i = left; i <= right; i++) res[x++] = matrix[top][i];
            if(++top > bottom) break;
            for(int i = top; i <= bottom; i++) res[x++] = matrix[i][right];
            if(left > --right) break;
            for(int i = right; i >= left; i--) res[x++] = matrix[bottom][i];
            if(top > --bottom) break;
            for(int i = bottom; i >= top; i--) res[x++] = matrix[i][left];
            if(++left > right) break;
        }
        return res;
    }
}