python 求眾數(shù) LeetCode N0.169

這道題有很多解法官方leetcode上面是六種，由于說的太過于詳細(xì)，我都不好意思，再補(bǔ)充什么了。所以我就寫了一點(diǎn)，沒看答案之前的寫法，和我覺得，需要掌握的寫法吧。他寫的很多代碼很精簡(jiǎn)，值得學(xué)習(xí)。（ps，納悶的是，即使我用的O（n）的復(fù)雜度，排名也很靠后哈哈哈哈哈）

            
              
                class
              
              
                Solution
              
              
                (
              
              
                object
              
              
                )
              
              
                :
              
              
                def
              
              
                majorityElement
              
              
                (
              
              self
              
                ,
              
               nums
              
                )
              
              
                :
              
              
                """
        :type nums: List[int]
        :rtype: int
        """
              
              
                #count = 0
              
              
                #candidate = None
              
              
                #for num in nums:
              
              
                #   if count == 0:
              
              
                #        candidate = num
              
              
                #    count += (1 if num == candidate else -1)
              
              
                #return candidate
              
              

        count 
              
                =
              
              
                0
              
              
        candidate 
              
                =
              
               nums
              
                [
              
              
                0
              
              
                ]
              
              
                for
              
               i 
              
                in
              
              
                range
              
              
                (
              
              
                len
              
              
                (
              
              nums
              
                )
              
              
                )
              
              
                :
              
              
                if
              
               nums
              
                [
              
              i
              
                ]
              
              
                ==
              
               candidate
              
                :
              
              
                count 
              
                +=
              
              
                1
              
              
                else
              
              
                :
              
              
                count 
              
                -=
              
              
                1
              
              
                if
              
               count 
              
                ==
              
              
                0
              
              
                :
              
              
                candidate 
              
                =
              
              nums
              
                [
              
              i
              
                +
              
              
                1
              
              
                ]
              
              
                return
              
               candidate

            
          

            
              
                class
              
              
                Solution
              
              
                (
              
              
                object
              
              
                )
              
              
                :
              
              
                def
              
              
                majorityElement
              
              
                (
              
              self
              
                ,
              
               nums
              
                )
              
              
                :
              
              
                """
        :type nums: List[int]
        :rtype: int
        """
              
              
                import
              
               math
        count 
              
                =
              
              
                {
              
              
                }
              
              
                if
              
              
                len
              
              
                (
              
              nums
              
                )
              
              
                %
              
              
                2
              
              
                ==
              
              
                1
              
              
                :
              
              
            n 
              
                =
              
              
                len
              
              
                (
              
              nums
              
                )
              
              
                +
              
              
                1
              
              
                else
              
              
                :
              
              
            n 
              
                =
              
              
                len
              
              
                (
              
              nums
              
                )
              
              
                for
              
               i 
              
                in
              
               nums
              
                :
              
              
            count
              
                [
              
              i
              
                ]
              
              
                =
              
               count
              
                .
              
              get
              
                (
              
              i
              
                ,
              
              
                0
              
              
                )
              
              
                +
              
              
                1
              
              
                if
              
               count
              
                [
              
              i
              
                ]
              
              
                >=
              
               n
              
                /
              
              
                2
              
              
                :
              
              
                return
              
               i
        
              
                for
              
               i 
              
                in
              
               nums
              
                :
              
              
                if
              
               count
              
                [
              
              i
              
                ]
              
              
                >=
              
               n
              
                /
              
              
                2
              
              
                :
              
              
                return
              
               i

            
          

            
              
                class
              
              
                Solution
              
              
                :
              
              
                def
              
              
                majorityElement
              
              
                (
              
              self
              
                ,
              
               nums
              
                )
              
              
                :
              
              
        counts 
              
                =
              
               collections
              
                .
              
              Counter
              
                (
              
              nums
              
                )
              
              
                return
              
              
                max
              
              
                (
              
              counts
              
                .
              
              keys
              
                (
              
              
                )
              
              
                ,
              
               key
              
                =
              
              counts
              
                .
              
              get
              
                )
              
              
                #作者：LeetCode
              
              
                #鏈接：https://leetcode-cn.com/problems/majority-element/solution/qiu-zhong-shu-by-leetcode-2/
              
              
                #來源：力扣（LeetCode）
              
              
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