More:【目录】LeetCode Java实现
https://leetcode.com/problems/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.
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
Use HashSet.
public boolean containsDuplicate(int[] nums) { if(nums==null || nums.length<=1) return false; HashSet<Integer> set = new HashSet<>(); for(int i : nums){ if(set.contains(i)){ return true; }else{ set.add(i); } } return false; }
Time complexity : O(n)
Space complexity : O(n)
More:【目录】LeetCode Java实现
【LeetCode】217. Contains Duplicate
原文:https://www.cnblogs.com/yongh/p/11636410.html