代码随想录70期day5

哈希表

242

class Solution:def isAnagram(self,s:str,t:str) -> bool:record = [0] * 26for i in s:record[ord[i] - ord("a")] += 1for i in t:record[ord[i] - ord("a")] -=1for i in range(26):if record[i] != 0:return Falsereturn True

349

class Solution:def intersection(self,nums1:List[int],nums2:List[int]) -> List[int]:table = {}for num in nums1:table[num] = table.get(num,0) + 1res = set()for num in nums2:if num in table:res.add(num)del table[num]return list(res)

202

class Solution:def isHappy(self,n:int) -> bool:record = set()while True:n = self.get_sum(n)if n == 1:return True if n in record:return Falseelse:record.add(n)def get_sum(self, n:int) -> int:new_num = 0while n:n,r = divmod(n,10)new_num += r**2return new_num

1

class Solution:def twoSum(self,nums:List[int],target:int) -> List[int]:records = dict()for index,value in enumerate(nums):if target - value in records:return [records[target - value], index]records[value]  = index return []