219.存在重复元素-ii.py

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# @lc app=leetcode.cn id=219 lang=python3
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# [219] 存在重复元素 II
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# https://leetcode-cn.com/problems/contains-duplicate-ii/description/
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# algorithms
# Easy (33.78%)
# Total Accepted:    12.1K
# Total Submissions: 35.7K
# Testcase Example:  '[1,2,3,1]\n3'
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# 给定一个整数数组和一个整数 k，判断数组中是否存在两个不同的索引 i 和 j，使得 nums [i] = nums [j]，并且 i 和 j
# 的差的绝对值最大为 k。
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# 示例 1:
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# 输入: nums = [1,2,3,1], k = 3
# 输出: true
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# 示例 2:
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# 输入: nums = [1,0,1,1], k = 1
# 输出: true
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# 示例 3:
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# 输入: nums = [1,2,3,1,2,3], k = 2
# 输出: false
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#
class Solution:
    def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:
        if len(nums)<1:
            return False
        dic = {}
        for i in range(len(nums)):
            if nums[i] in dic:
                if i - dic[nums[i]] <=k:
                    return True
            dic[nums[i]] =i
        return False