剑指 Offer 29. 顺时针打印矩阵

剑指 Offer 29. 顺时针打印矩阵

遍历，设置边界

执行用时：1 ms, 在所有 Java 提交中击败了97.38% 的用户 内存消耗：39.6 MB, 在所有 Java 提交中击败了73.08% 的用户

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