Algorithms exist practice of repeating elements

Algorithm topic:

The following sources: https: //leetcode-cn.com/problems/contains-duplicate-ii

Given an array of integers and k an integer, whether there are two different indices i and j is determined array, such nums [i] = nums [j], and the maximum absolute value of the difference is k i and j.

Example 1:

Input: the nums = [1,2,3,1], K =. 3
to true: Output
Example 2:

Input: the nums = [1,0,1,1], K =. 1
to true: Output
Example 3:

Input: nums = [1,2,3,1,2,3], k = 2
Output: false

 

python3 Code:

class Solution:
    def containsNearbyDuplicate(self, nums, k):
        #先判断是否存在重复元素
        nums_len=len(nums)
        set_len=len(set(nums))
        if set_len == nums_len:
            return False
        elif set_len < nums_len:
            for i in range(nums_len):
                for j in  range(i+1,nums_len):
                # for j in  range(nums_len-i):
                    if nums[i] == nums[j]:
                        if abs(i-j)<=k:
                            # print(i ,j)
                            return True
            return False

Summarize ideas and knowledge

1.2 for determining layer for loop start value

for i in range(nums_len):
    for j in  range(i+1,nums_len):

2. Under what circumstances returns False

3. code coverage as more test cases and the array length is zero for the case where the 1 [] [1]

4.set tuple string of digital dictionaries list the commonly used method to master several data structures