Hot-169 多数元素

解法1用一个dict 或者 mapclass Solution: def majorityElement(self, nums: List[int]) - int: n len(nums) half n // 2 myMap {} for num in nums: if num not in myMap: myMap[num] 1 else: myMap[num] 1 if myMap[num] half: return num return nums[0]解法2采用投票抵消(非常巧妙)class Solution: def majorityElement(self, nums: List[int]) - int: count 0 number None for num in nums: # 分情况进行投票 if count 0: count 1 number num elif num number : count 1 else: count -1 return number解法3sort 取index sum//2class Solution: def majorityElement(self, nums: List[int]) - int: nums.sort() return nums[len(nums)//2]