Leetcode 3694. Distinct Points Reachable After Substring Removal

• Leetcode 3694. Distinct Points Reachable After Substring Removal
  • 1. 解题思路
  • 2. 代码实现

• 题目链接：3694. Distinct Points Reachable After Substring Removal

1. 解题思路

这一题思路上就是一个滑动窗口的思路，我们首先计算出终点的位置，然后考察每一个连续长为$k$的窗口的位移改变量，然后减去对应的改动量即可。

2. 代码实现

给出python代码实现如下：

class Solution:def distinctPoints(self, s: str, k: int) -> int:mapping = {"U": [0, 1], "D": [0, -1], "L": [-1, 0], "R": [1, 0]}cord = [0, 0]for ch in s:cord = [x+d for x, d in zip(cord, mapping[ch])]ans = set()delta = [0, 0]for i, ch in enumerate(s):delta = [x+d for x, d in zip(delta, mapping[ch])]if i-k >= 0:delta = [x-d for x, d in zip(delta, mapping[s[i-k]])]if i >= k-1:ans.add((cord[0]-delta[0], cord[1]-delta[1]))return len(ans)

提交代码评测得到：耗时1447ms，占用内存26.8MB。