README_EN.md

217. Contains Duplicate

中文文档

Description

Given an array of integers, find if the array contains any duplicates.

Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.

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

Solutions

Python3

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        return len(nums) != len(set(nums))

Java

class Solution {
    public boolean containsDuplicate(int[] nums) {
        Set<Integer> set = new HashSet<>();
        for (int e : nums) {
            if (set.contains(e)) return true;
            set.add(e);
        }
        return false;
    }
}

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