leetcode 217. Contains Duplicate 求一个数组中有没有重复元素 ---------- java

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.

1、暴力枚举。

2、sort

public class Solution {
    public boolean containsDuplicate(int[] nums) {
        Arrays.sort(nums);
        for (int i = 1; i < nums.length; i++){
            if (nums[i] == nums[i - 1]){
                return true;
            }
        }
        return false;
    }
}

3、set