update

Author: ncdhz

code/306.累加数.py

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+#
+# @lc app=leetcode.cn id=306 lang=python3
+#
+# [306] 累加数
+#
+
+
+# @lc code=start
+class Solution:
+
+ def _add(self, s1, s2):
+ s1l = len(s1)
+ s2l = len(s2)
+ s = 0
+ res = ''
+ for i in range(1, max(s1l, s2l) + 1):
+
+ a = s1[s1l - i] if i <= s1l else 0
+ b = s2[s2l - i] if i <= s2l else 0 
+ x = int(a) + int(b) + s
+ s = 0
+ if x >= 10:
+ s = 1
+ x %= 10
+ res = f'{x}{res}'
+
+ if s == 1:
+ res = f'1{res}'
+
+ return res
+
+
+ def _isAdditiveNumber(self, i, j, num):
+ s = self._add(num[: i], num[i: i + j])
+ 
+ n = num[i + j:]
+ if n.startswith(s):
+ if len(n) == len(s):
+ return True
+ else:
+ return self._isAdditiveNumber(j, len(s), num[i:])
+ return False
+
+ def isAdditiveNumber(self, num: str) -> bool:
+ if len(num) < 3:
+ return False
+
+ n2 = len(num) // 2 + 1
+ for i in range(1, n2):
+ if num[0] == '0' and i > 1:
+ break
+ for j in range(1, n2):
+ if num[i] == '0' and j > 1:
+ break
+ if i + j == len(num):
+ return False
+ if self._isAdditiveNumber(i, j, num):
+ return True
+ 
+ return False
+# @lc code=end

code/307.区域和检索-数组可修改.py

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+#
+# @lc app=leetcode.cn id=307 lang=python3
+#
+# [307] 区域和检索 - 数组可修改
+#
+
+# @lc code=start
+class NumArray:
+
+ def __init__(self, nums: List[int]):
+ self.__data = []
+ self.__nums = nums
+ self.__update = {}
+ sum_ = 0
+ for num in nums:
+ sum_ += num
+ self.__data.append(sum_)
+
+ def update(self, index: int, val: int) -> None:
+ self.__update[index] = val
+ if len(self.__update) == 500:
+ for key in self.__update:
+ self.__nums[key] = self.__update[key]
+
+ self.__data = []
+ sum_ = 0
+ for num in self.__nums:
+ sum_ += num
+ self.__data.append(sum_)
+ self.__update = {}
+
+ def sumRange(self, left: int, right: int) -> int:
+ l = self.__data[left - 1] if left - 1 >= 0 else 0
+ sum_ = self.__data[right] - l
+ for i in self.__update:
+ if left <= i <= right:
+ sum_ += self.__update[i] - self.__nums[i]
+ return sum_
+
+# Your NumArray object will be instantiated and called as such:
+# obj = NumArray(nums)
+# obj.update(index,val)
+# param_2 = obj.sumRange(left,right)
+# @lc code=end
+

code/309.买卖股票的最佳时机含冷冻期.py

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+#
+# @lc app=leetcode.cn id=309 lang=python3
+#
+# [309] 买卖股票的最佳时机含冷冻期
+#
+
+# @lc code=start
+class Solution:
+ def maxProfit(self, prices: List[int]) -> int:
+ if len(prices) == 1:
+ return 0
+ 
+ buy = -prices[0]
+ stop = 0
+ sell = 0
+
+ for price in prices[1:]:
+ buy, stop, sell = max([stop - price, buy]), max([stop, sell]), max([buy + price, sell]) 
+ 
+ return max([stop, sell])
+# @lc code=end

code/310.最小高度树.py

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+#
+# @lc app=leetcode.cn id=310 lang=python3
+#
+# [310] 最小高度树
+#
+
+from collections import deque
+# @lc code=start
+class Solution:
+
+ def heightTree(self, i, n, tree):
+ 
+ deques = deque([i])
+ visits = {i}
+ paths = [-1] * n
+ while len(deques):
+ node = deques.popleft()
+ ns = tree.get(node)
+ for n in ns:
+ if n not in visits:
+ visits.add(n)
+ paths[n] = node
+ deques.append(n)
+ return node, paths
+
+ def findMinHeightTrees(self, n: int, edges: List[List[int]]) -> List[int]:
+ 
+ if n == 1:
+ return [0]
+ 
+ tree = {}
+ for edge in edges:
+ tree.setdefault(edge[0], []).append(edge[1])
+ tree.setdefault(edge[1], []).append(edge[0])
+ 
+ x, _ = self.heightTree(0, n, tree)
+ y, paths = self.heightTree(x, n, tree)
+ 
+ ps = []
+ while paths[y] != -1:
+ ps.append(y)
+ y = paths[y]
+ ps.append(x)
+
+ psl2 = len(ps) // 2
+ res = [ps[psl2]] 
+ if len(ps) % 2 == 0:
+ res.append(ps[psl2 - 1])
+ return res
+
+# @lc code=end