Duplicate-优快云博客

本文链接：https://blog.youkuaiyun.com/eilot_c/article/details/106858086

本文深入解析了Python中几种核心算法的实现，包括检测数组中是否有重复元素、寻找字符串中最长的回文子串以及判断数组中是否存在k距离内的重复元素。通过具体的代码示例，详细阐述了每种算法的思路和实现过程。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

是否存在相同元素，python3用字典的方式解决

class Solution(object):
    def containsDuplicate(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        # 方法3：数字存字典
        dic = {}
        for i in nums:
            dic[i] = dic.get(i, 0) + 1
            if dic[i] > 1:
                return True
        return False

最长回文子串

class Solution:
    def longestPalindrome(self, s: str) -> str:
        # 两种判断条件
        # DP 动态规划
        # CABAC
        # B
        # ABA
        # CABAC
        palindrome = ''
        for i in range(len(s)):
            aa1 = self.getlongestpalindrome(s,i,i)
            len1 = len(aa1)
            if len1>len(palindrome):
                palindrome = aa1
            aa2 = self.getlongestpalindrome(s,i,i+1)
            len2 = len(aa2)
            if len2>len(palindrome):
                palindrome = aa2
        
        return palindrome

    
    def getlongestpalindrome(self, s, l, r):
        while l >= 0 and r<len(s) and s[l]==s[r]:
            l -= 1
            r += 1
        return s[l+1:r]

~

class Solution:
    def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:
        # 用dictionary来做比较容易一点
        lookup = {}
        for i , num in enumerate(nums):
            if num not in lookup:
                lookup[num] = i # 将num存到dic里面
            else:
                if i-lookup[num]<=k:
                    return True
                lookup[num] = i
        return False
        

~