# [leetcode] 38. There are duplicate elements - Java version

2021-08-26 16:37:32

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java Set Self weight removal , If the length after weight removal is less than the original length , Then return to true

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## Preface

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Confused algorithm , A rare confused

## Question

#### 217. There are duplicate elements

difficulty ： Simple

Given an array of integers , Determine whether there are duplicate elements .

If a value exists, it appears at least twice in the array , The function returns true . If every element in the array is different , Then return to false .

Example 1:

`````` Input : [1,2,3,1]
Output : true
``````

Example 2:

`````` Input : [1,2,3,4]
Output : false
``````

Example 3:

`````` Input : [1,1,1,3,3,4,3,2,4,2]
Output : true
``````

## Solution

hashset

• utilize hashset The principle of weight removal
• If you return... When adding an element `false`, There is

## Code

all `leetcode` Code synchronized to github

welcome `star`

``````/** * @author yitiaoIT */
class Solution {

public boolean containsDuplicate(int[] nums) {

Set<Integer> set = new HashSet<Integer>();
for (int x : nums) {

return true;
}
}
return false;
}
}
``````

## Result

Complexity analysis

• Time complexity ：O(N)

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