Re: [閒聊] 每日leetcode

[dont (dont)]

885. Spiral Matrix III

## 思路

模擬題, 東南各1步 西北各2步 東南各3步...etc

如果當前的位置在rows, cols範圍內就加進res

## Complexity

Time: O(Rows * Cols)
Space: O(1)

## Code

1.
dirs = [(0, 1), (1, 0), (0, -1), (-1, 0)]
dx, dy = dirs[k]

```python
class Solution:
    def spiralMatrixIII(self, rows: int, cols: int, rStart: int, cStart: int)
-> List[List[int]]:

        dirs = [(0, 1), (1, 0), (0, -1), (-1, 0)]
        ans = []
        count = rows * cols
        size = 1

        while count:

            for k in range(4):
                for _ in range(size):
                    if 0 <= rStart < rows and 0 <= cStart < cols:
                        ans.append([rStart, cStart])
                        count -= 1
                    rStart += dirs[k][0]
                    cStart += dirs[k][1]
                if k & 1:
                    size += 1
                if count == 0:
                    break

        return ans
```

2. dx, dy = dy, -dx

```python
class Solution:
    def spiralMatrixIII(self, rows: int, cols: int, rStart: int, cStart: int)
-> List[List[int]]:

        dx, dy = 0, 1
        ans = []
        count = rows * cols
        size = 1

        while count:
            for _ in range(size):
                if 0 <= rStart < rows and 0 <= cStart < cols:
                    ans.append([rStart, cStart])
                    count -= 1
                rStart += dx
                cStart += dy

            dx, dy = dy, -dx
            if dx == 0:
                size += 1

        return ans
```

--
http://i.imgur.com/OLvBn3b.jpg

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※ 編輯: dont (185.213.82.160 臺灣), 08/08/2024 13:53:05
推 smart0eddie: space 你是排除輸出嗎
→ dont: ？ 跟你的寫法一樣？