40 lines
1.2 KiB
Java
40 lines
1.2 KiB
Java
# 29. 顺时针打印矩阵
|
||
|
||
[NowCoder](https://www.nowcoder.com/practice/9b4c81a02cd34f76be2659fa0d54342a?tpId=13&tqId=11172&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking&from=cyc_github)
|
||
|
||
## 题目描述
|
||
|
||
下图的矩阵顺时针打印结果为：1, 2, 3, 4, 8, 12, 16, 15, 14, 13, 9, 5, 6, 7, 11, 10
|
||
|
||
<div align="center"> <img src="pics/48517227-324c-4664-bd26-a2d2cffe2bfe.png" width="200px"> </div><br>
|
||
|
||
## 解题思路
|
||
|
||
```java
|
||
public ArrayList<Integer> printMatrix(int[][] matrix) {
|
||
ArrayList<Integer> ret = new ArrayList<>();
|
||
int r1 = 0, r2 = matrix.length - 1, c1 = 0, c2 = matrix[0].length - 1;
|
||
while (r1 <= r2 && c1 <= c2) {
|
||
for (int i = c1; i <= c2; i++)
|
||
ret.add(matrix[r1][i]);
|
||
for (int i = r1 + 1; i <= r2; i++)
|
||
ret.add(matrix[i][c2]);
|
||
if (r1 != r2)
|
||
for (int i = c2 - 1; i >= c1; i--)
|
||
ret.add(matrix[r2][i]);
|
||
if (c1 != c2)
|
||
for (int i = r2 - 1; i > r1; i--)
|
||
ret.add(matrix[i][c1]);
|
||
r1++; r2--; c1++; c2--;
|
||
}
|
||
return ret;
|
||
}
|
||
```
|
||
|
||
|
||
|
||
|
||
|
||
|
||
<div align="center"><img width="320px" src="https://cs-notes-1256109796.cos.ap-guangzhou.myqcloud.com/githubio/公众号二维码-2.png"></img></div>
|