Leetcode 217. Contains Duplicate

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.

标签 Array Hash Table

类似题目 (E) Contains Duplicate II (M) Contains Duplicate III

 

 

 

代码：

方法一：

public class Solution {
    public boolean containsDuplicate(int[] nums) {
        Set<Integer> hs = new HashSet<Integer>();
        for (int i = 0; i < nums.length; ++i) {
            if (hs.contains(nums[i])) {
                return true;
            }
            hs.add(nums[i]);
        }
        return false;
    }
}

方法二：

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;
    }
}